By GINGER THOMPSON
 
DOUGLAS, Ariz. — They were barely old enough to cross a street by themselves, much less a border. But there they were, alone on a hot August evening at a United States immigration checkpoint, surrounded by law enforcement officers wearing badges and guns. Eight-year-old José Cruz Velázquez held the hand of his brother Sergio, who was 6.

The Mexican boys had been seized from a smuggler hired by their parents living without legal papers in Pennsylvania. They were two of a growing number of children traveling without families who have been snared in the net that American and Mexican agents cast to stop illegal immigrants from crossing the border.

Authorities attribute the trend to aggressive American law enforcement operations during the past decade that have effectively sealed long sections of the 2,000-mile border. The blockade was further reinforced after the terrorist attacks in the United States on Sept. 11, 2001.

The tightened security has made it much harder for illegal immigrants to move back and forth across the border, disrupting long-established migration patterns.

Immigrants who lack American documents have been forced to cross through remote desert. Smugglers who lead them, called coyotes, have tripled their fees in the last decade, experts said.

As a result, parents living in the United States illegally find increasingly that they can no longer afford the growing risks and expense of returning home to retrieve their children. They face a harsh choice: either they allow others to raise their children far away, or they hire strangers to smuggle their children into the United States.

"If my children stay in El Salvador, I will definitely lose them because of the distance that separates us," said Rigoberto Centeno, a Salvadoran immigrant who lives in the Washington suburbs and who recently hired a smuggler to help reunite his family. "If they come with a coyote to the United States, there is a chance that I will lose them in the desert.

"But there is also a very good chance that they will make it across. If we want to be with our children, there is no other way."

American officials warn that immigrant parents are leaving themselves and their children vulnerable to smugglers' abuses.

"These are not Robin Hoods who are interested in helping families," said Joseph Greene, deputy assistant director for smuggling and public safety at United States Immigration and Customs Enforcement. "They are cold-blooded capitalists. The smugglers have seen children as the next important exploitable population."

For generations, illegal immigrants from Latin America worked seasonally in the United States, returning home for part of each year. Others who settled more permanently north of the border made regular trips to visit loved ones back home.

Now military-style Border Patrol operations — complete with steel walls, helicopters, infrared cameras and motion detectors — have practically shut down the western stretch of the border near San Diego and the eastern region around El Paso. The scorching desert here, between Arizona and the Mexican state of Sonora, has become the main gateway for illegal immigrants. An average of one immigrant a day died last summer trying to cross illegally in this area — a record number.

Despite the dangers, more and younger children are being detained during attempts to cross. This year, through the end of September, Mexican consular authorities had repatriated more than 9,800 unaccompanied Mexican minors under the age of 17 who were caught crossing illegally, according to Juan Miguel Gutiérrez Tinoco, director general of protection and consular affairs at the Mexican Foreign Ministry. In all of last year, Mexico repatriated about 9,900 unaccompanied minors.

The number of unaccompanied children under 13 who were repatriated rose from 1,300 in 2002 to more than 1,500 at the end of September.

While repatriations of unaccompanied minors have declined along the reinforced sectors of the border, in Arizona the number has risen to more than 2,300 so far this year from 975 in 2001, the Mexican figures show.

Officials say the number of children crossing is much higher, because a great majority of illegal immigrants pass successfully, undetected by the border police. Indeed, some officials argue that the flow of children has been high for years and that increased apprehensions reflect stricter border controls rather than a rise in the numbers of children who cross.

A Risk Worth Taking

To the parents of Sergio and José Cruz Velázquez, who had made a new home in a city in Pennsylvania, the pain of separation from the boys outweighed the risks of a journey with a smuggler.

"I did not feel good when my sons were so far away," said Rosa Velázquez, the boys' mother. "I wanted them with me." She and her husband agreed to pay a smuggler $5,000 to bring the boys across.

"We never talked about the danger," Mrs. Velázquez said. "Both of us have crossed the border with coyotes. We know that it is difficult. But we believed that our sons would be fine."

Following a common pattern, they had their sons sent with no official documents that could tip off the police to their real identities. The smuggler escorting them tried to sneak them across the border with false papers, claiming they were his nephews. He had no information on how to contact their parents, only the first name and cellphone number of another coyote who was supposed to receive the boys on the American side.

After the boys were captured, Miguel Escobar, the Mexican consul based in Douglas, pried that number out of the smuggler and called it, informing a voice on the line that he had taken custody of the children.

Late that night, Mr. and Mrs. Velázquez were awakened in Pennsylvania by a call from a relative at the border, who had learned that the boys had been detained. The parents were overcome with regret.

"I asked myself, what did we do?" Mrs. Velázquez recalled.

Meanwhile, in Agua Prieta, a shabby Mexican border town directly across from Douglas, Mr. Escobar drove the boys to a child welfare shelter, set behind a barred fence on an unpaved street. From a distance, it looked more like a prison than a refuge. The boys pleaded with Mr. Escobar not to leave them there. The next day, a shelter worker said they had hardly touched their breakfast.

When asked in an interview how it had been for them to face the American border police officers, José Cruz shook his head to say he was not afraid, and summoned an unconvincing smile. But Sergio held nothing back.

"My legs were shaking," he said, his eyes filling with tears. "I want to see my mama."

Mr. Escobar has come to dread the sound of his mobile telephone. It rings to summon him to gather up lost children — so many that their stories are hard to keep straight in his head.

It rang on the first Saturday in September about 1 p.m. In temperatures that soared past 100 degrees, United States Border Patrol officers had found a 5-year-old in pigtails, Karen Tepas, walking with six adults across a stretch of desert 10 miles east of Douglas. When Mr. Escobar arrived, Karen was crying for her mother.

The adults captured with her told American agents that during the hike Karen had been separated from her mother, who was seven months pregnant and had fallen behind. Karen was captured without her. Mr. Escobar tried to comfort the child, then drove her to the shelter.

Another call took him back to the Douglas checkpoint, where American officers were holding Karla Tafolla, age 7, and her brother Roberto, just over a year old. They had been seized from a 56-year-old woman who presented false documents in claiming they were her grandchildren.

The officers brought out graham crackers and puppets. They tried, unsuccessfully, to coax some information from the children about their parents' location. Karla enjoyed being the center of attention as Roberto toddled about.

In the office next door, Mr. Escobar was losing patience with the suspected smuggler, a rumpled woman with dyed red hair. He lowered his voice and moved in close. "I do not have any interest in giving you more problems," he said. "I am here to help these children."

Finally the woman provided a Phoenix mobile phone number for the children's father. Then she lowered her voice as well.

"Is there something you can do to help me, too?" she asked.

Most of the suspects arrested on charges of smuggling children in the last year along this part of the border have been women with no criminal records, said Paul Charleton, the United States attorney for the district of Arizona. Typically they were American citizens, or Mexicans with legal status in the United States that allowed them to move easily across the border. Most were small-time operators, out for a quick buck.

While smugglers generally try to skirt the Border Patrol by trekking through the desert, those dealing with children often hide in plain sight, driving or walking through border checkpoints crowded with customs and immigration officers. The coyotes present legal documents belonging to other children to pass their charges as relatives.

Often smugglers are loosely linked to chains of human traffickers that stretch across Mexico and into the Latin continent. Children who were smuggled into the United States reported traveling with a series of strangers. They moved northward on buses or as stowaways on freight trains and vegetable trucks, staying in safe houses and fleabag hotels, sometimes for only a few hours.

Their parents reported paying fees from $2,000 for a child from Mexico to as much as $7,000 for children from Central America.

While some smugglers take extra care when they are moving children, others are dangerously callous. Early this year, two children nearly suffocated in the trunk of a car caught crossing the desert illegally.

'A Dangerous Situation'

Both American and Mexican officials complain that child smuggling has not been treated as a serious crime. "Anytime a stranger is entrusted with a child, it is a dangerous situation," Mr. Charleton said in an interview. "And when a stranger is entrusted to take a child across an international border that danger is magnified."

Robert Miskell, chief of the criminal division of the United States attorney's office in Tucson, said first-time offenders were likely to get more jail time for sneaking an 85-pound sack of marijuana across the border than a 50-pound child.

Since the beginning of the year, when the Tucson office made enforcement against child smuggling a top priority, only one smuggler has been tried and convicted, drawing a sentence of six months in jail, Mr. Miskell said. Most others pleaded guilty and were released after a month or two in jail.

In Central America, child smuggling has become the focus of public debate. In the first eight months of this year, authorities in Mexico detained more than 2,900 minors from Central America who were traveling illegally with smugglers, according to Mexico's National Migration Institute.

Unicef has joined with the government in El Salvador to sponsor a public awareness campaign about the dangers. It features radio spots broadcast by 118 stations across Central America, and a comic book with an opening chapter titled, "I turned my grandson over to a stranger."

Early in September, Salvadoran authorities summoned news organizations to the international airport to publicize the return of two children deported from Mexico.

Rigoberto Centeno had agreed to pay $10,000 to a smuggler to deliver his son Emmanuel, 11, and his 6-year-old granddaughter, María Ivania, to his home near Washington, where he has lived for most of the last 15 years. But near Monterrey, Mexico, authorities seized the children and a coyote from a commercial bus.

They spent five weeks in a Mexican shelter before being sent home. Mr. Centeno returned to El Salvador to receive them because he feared authorities there would not turn them over to anyone else.

But he was not swayed by the government campaign. Speaking defiantly to reporters, he said his only regret was that the children did not make it to the United States. He said depictions of smugglers as ruthless criminals were overblown.

He and his wife "saw other people, our neighbors hiring coyotes for their children," he said. "So we thought, why not us? We want the same things."

His main concern was to hold on to his American job, as a supervisor at an office cleaning company. "If I lose that," he said, "then the entire family loses."

He embraced the bewildered children. "They are probably going to be scared for a little while," he acknowledged. But he vowed to return alone to Washington and send for them soon, again with a coyote.

Mexican and American authorities say that immigrant parents often undermine their efforts. In Agua Prieta, Bilha Villalobos runs a shelter that takes in many of the children the Border Patrol finds. Most times, she lamented, it operates like a big revolving door. Children come in from the border for a few days. Parents call with urgent promises, saying they have learned their lesson and will send their children straight back to homes in Mexico.

But when the children are released, their parents give them back to smugglers for another try at crossing.

"We try to protect the children the best that we can," said Ms. Villalobos, director of the Casa Y.M.C.A. "But the parents deceive us."

One parent who made such promises was María Concepción García. Her daughter Abigail, then 12, arrived in the Casa Y.M.C.A. one day in early August, hungry and dehydrated.

Abigail had been captured by American border agents before dawn, walking with a small group of immigrants through the desert near the town of Naco. After three days in the desert, her lips were so chapped they had begun to scab.

In an interview at the shelter, Abigail said she had come to the border from Guerrero, one of Mexico's poorest states, and was on her way to live with her mother on Long Island.

Abigail, who showed an infectious smile despite her circumstances, said she had not been mistreated by any of the strangers she met on her journey. She said she was scared, "just a little," by snakes that crawled through the sand at night.

A Mother's Heartache

But she hinted at severe hardships she had seen on the trip. "One woman fainted," she said. "We had to stop for a long time. They gave her cucumber and banana. There was no more water."

Still, Abigail insisted she was ready to try again. "I want to live with my mama," she said firmly. "I have not seen her for a long time."

Her mother, Ms. García, had immigrated to the United States seven years earlier. She soon settled in New York State, making a home with a landscaper from El Salvador who also lacked legal papers, and the couple had three children. But Ms. García always longed for three children she had left behind in Mexico. (Abigail was the second to come.)

"I felt bad every time I did something for my children here because I could not do the same for my children there," Ms. García said, speaking in a park near her home on Long Island. She described sleepless nights worrying whether Abigail was eating well and staying in school.

So two days after she received word that Abigail had been stopped at the border, Ms. García faxed a letter to Casa Y.M.C.A., authorizing the shelter to release Abigail to a woman she named as Neyed Yunuen Sánchez Guerrero. She wrote that Ms. Sánchez would ride with Abigail by bus back to Mexico City, where Abigail's grandmother would be waiting to take her the rest of the way home.

Casa Y.M.C.A. followed the instructions, but the woman who retrieved Abigail never looked for a bus. She delivered the child, by agreement with her mother, to a new smuggler, and hours later Abigail was walking again under a clear desert sky toward Arizona.

Then the girl's journey took a turn Ms. García did not expect.

For the next four days, she lost contact with Abigail and the smuggler. They did not call, and no one answered the smuggler's cellphone.

"I could not eat," Ms. García said. "I could not sleep. One night, I stayed out in front of the house, waiting for Abigail to arrive."

On the fifth day Ms. García got a call from a stranger.

"I have your daughter," said a voice she had never heard before. "But give thanks to God that she fell into the hands of a family man. Some coyotes would abuse a girl like this one."

The man told Ms. García that Abigail had become hysterical. She refused to eat, take a bath or put on clean clothes, and she would not stop crying.

Ms. García pleaded with the smuggler to bring Abigail to New York. Even though she had already paid $500 as a deposit to the smuggler who first brought Abigail to the border, Ms. García quickly offered $2,000 to the new one.

"No more tricks, no more lies," Ms. Garcia said. "Bring my daughter to me."

The coyote put Abigail on the phone. She said she was crying because she did not know anyone and was scared. She reminded her mother that her 13th birthday was only five days away, on Aug. 17.

"I thought I would already have seen your face," the girl said.

Abigail's birthday came and went. All her mother knew was that she was in a house somewhere in Phoenix.

But the coyote kept his agreement. Four days after Abigail's birthday, she was dropped off behind a Home Depot store on Long Island. Ms. García took Abigail straight home and celebrated her birthday with a meal of turkey in a homemade Mexican sauce.

The next morning, Abigail was splashing happily in a neighborhood pool, making new friends.

Of course, Ms. García said as she watched her daughter play, she had thought about the risks of losing Abigail during her journey north. "It is hard to explain," Ms. García said. "Maybe I was blind because I wanted her with to be with me."

An Agonizing Decision

The parents of José Cruz and Sergio Velázquez were driven by the same determination. After learning of their sons' detention in Agua Prieta, Rosa Velázquez agonized. "I told my husband that maybe we should leave the boys in Mexico," she said. "Maybe it was too dangerous." It was an option the parents could not accept. They sought another smuggler. By the end of August, the boys had reached their new home.

In an interview a few days after their arrival in a gritty neighborhood of row houses, Mrs. Velázquez was amazed and thankful. She beamed at the boys in their new bedroom, furnished with only a mattress and an image of the Virgin of Guadalupe, the patroness of Mexico, but littered with toys sent by the neighbors. "This is a dream," she said. "Thank God my sons were in the hands of a good coyote."

José Cruz seemed transformed. His smile stretched from ear to ear. When asked about their journey, however, the boys scurried to their bedroom and slammed the door shut. "They do not talk about it, not even with me," Mrs. Velázquez said. "They tell me that they just want to forget."