By Danna Harman | Staff writer of The Christian Science Monitor

NUEVO LAREDO, MEXICO; AND LAREDO, TEXAS - They were just three births shy of 4,000 last year at the Laredo Medical Center maternity ward here in Texas. Three thousand nine hundred ninety-seven healthy, screaming new American citizens, of whom, estimates Armida "Armi" Calvillo, chief nurse, about half were born to visiting Mexican moms.

Mexican madres giving birth in US maternity wards in order to obtain better care - and blue passports - for their offspring, is as old as the border itself. But in recent months, say staff here, it's been increasing - in direct proportion, they suggest, to growing crime and insecurity in towns on the Mexican side. Another indicator: Real estate agents in Laredo report more wealthy Mexicans crossing the Rio Grande to house hunt, seeking a haven for their families.

"There are definitely more women coming over," says Carmen Hernandez, a technician in the ward, who herself is originally from Nuevo Laredo, Mexico, just across the border. "With the situation so bad over there, wouldn't you make that journey?"

The US State Department issued a travel advisory on Jan. 21 warning US citizens of "increased violence among drug traffickers" along the 2,000-mile US-Mexico border. But overwhelmingly, Mexicans are being most acutely hurt by the recent security crisis.

More than 115 Mexicans have been reported kidnapped or missing along the border area stretching eastward to Matamoros in the past six months. At least that many incidents have gone unreported, according to the Center for Frontier Studies and Human Rights in Reynosa. Since Jan. 1, 26 people have been killed in violence attributed to competing drug lords Joaquin "El Chapo" Guzmán, head of the Sinaloa cartel, and Osiel Cárdenas, the imprisoned leader of the Gulf cartel.

In Nuevo Laredo, every day this week the local papers have led with reports of murders: A police officer's sister killed on Monday, the remains of a 30-year-old woman found on the dirt road leading out of town on Tuesday, and so on.

Many more stories go untold. That's because journalists, too, have been increasingly targeted. Six months ago, editor Roberto Mora, whose newspaper, El Mañana, had published stories about the Gulf cartel, was found stabbed outside his home in Nuevo Laredo. A month later, syndicated columnist Francisco Arratia Saldierna's body was dumped in Matamoros. Just this week, gunmen in nearby Monterrey opened fire on reporter Jorge Cardona Villegas of TV station Televisia, which had just come out with a report on criminal activity in Reynosa. [Editor's note: The original version incorrectly located Matamoros in Texas.]

"Mexican citizens living in border towns like Tijuana, Juarez, and Nuevo Laredo have been victims of drug-related violence for a long time," says Laurie Freeman, Mexico associate at the Washington Office on Latin America (WOLA). "People just assume they were involved in the drug trade and leave it at that." But increasingly, she says, innocent bystanders are getting caught in the crossfire. "The drug cartels ... are becoming so powerful that they can pretty much do what they like and no authority will stop them," she says.

"These days, we hang in Laredo, [Texas]," says Isidro, a 24-year-old in a leather jacket with slicked-back hair, as he leaves his parents' home in Nuevo Laredo for a night out across the border. "You grow up here, hearing about 'drug lords this and that,' " he says, "but you could stay clear of it. Now the gangs want money and just reach out and get it." He and his group of friends - all from wealthy families - feel anxious about going out in their hometown.

"They know who's who," says Isidro, who asked that his last name not be used for security reasons. "The gangs scope you out at clubs, ask others about you, then come up to you when you are getting into your car." It's not tourists being targeted, he stresses, "because [the criminals] don't know enough about the gringos.... It's us they want."

Those who can afford to, like Isidro's parents, are house hunting on the US side. "It's as if the end of the world was nearing," says Ana Salinas, a real estate agent in Nuevo Laredo with Texas Realty Co., who herself lived on the Mexican side until last year. She has shown twice as many lots and three times as many houses this month as last, and her new customers are overwhelmingly from Mexico, she says. For many of them, says Ms. Salinas, the US homes are a place to leave wives and children while the men continue to work in Mexico. "They are afraid," she says, "they tell me so, straight out."

According to the Austin Office of Economic Development and Tourism, Laredo and Texas border towns McAllen (across from Reynosa) and Brownsville (across from Matamoros) are among the fastest-growing metropolitan areas in the US, in large part because of this influx from across the border.

Meanwhile in Mexico, it's a different story. At least 70 shops are up for rent in downtown Nuevo Laredo, says Fernando Villarreal, a local real estate agent. Two or three years ago, he says, there was no space to be found. The number of homes for sale has risen by at least 20 percent, he estimates, and prices are falling. Meanwhile, the hotels in town are running at 20 to 30 percent occupancy, according to the local Hilton.

It's Saturday night and the three border bridges spanning the Rio Grande here are jammed with pickups, cars, and pedestrians - the vast majority heading north. The usual hangouts on the Nuevo Laredo side - Hamilton's, the "F" bar, Harry's - are empty. The in-house cartoonist at El Dorado's is mindlessly sketching the band members, who sit, bored, up on their rickety stage, waiting for customers to show up. Isidro has picked up his girlfriend, crossed the border into Texas in his black Carerra, and is heading up I-35 to "Bourbon Street," a new favorite hang out, "on the safe side" as he calls it.

Over in the maternity ward, it's a busy night: five births. All of the mothers gave addresses in Laredo, but none spoke a word of English. Most likely, guesses Ms. Calvillo, none are from the US.

"That's life on the border," she shrugs. "It's not our role to find out who they are or why there are here or why more seem to be coming across now.... We just do what we do and say: 'Welcome to this world, little child.' "

• Ms. Harman is Latin America bureau chief for the Monitor and USA Today.