As Haitian President Jean-Bertrand Aristide goes into exile, U.S. Marines land in Haiti and a U.N. military force is being assembled to patrol the country.

BY NANCY SAN MARTIN, TRENTON DANIEL AND MARTIN MERZER

PORT-AU-PRINCE -- U.S. Marines landed in Haiti's chaotic, bullet-pocked capital Sunday night, the vanguard of a United Nations peacekeeping force still being assembled to calm the rebellion that ousted President Jean-Bertrand Aristide in less than a month.

A transitional government led by Haitian Supreme Court Justice Boniface Alexandre assumed power, without much initial success.

As word spread of Aristide's resignation and flight to asylum, hundreds of residents launched a new fusillade of revenge and opportunism, killing people, looting businesses and torching the homes of Aristide loyalists.

Men identifying themselves as rebels, some dressed in civilian clothing, others in camouflage, were seen in the capital.

At the end of an extraordinarily eventful day, about 200 Marines in full combat gear arrived at Port-au-Prince's airport Sunday night, with more to follow.

They were assigned to secure the airport and seaport, easing the way for more international troops, the delivery of humanitarian aid and the repatriation of Haitian migrants, officials said.

''I have ordered the deployment of Marines, as the leading element of an interim international force, to help bring order and stability to Haiti,'' President Bush said in Washington.

Late Sunday, the U.N. Security Council voted 15-0 to authorize an international military force to remain in Haiti for three months to restore order, followed by a more formal U.N. stabilization force.

France, Canada and some Caribbean nations were expected to join the U.S. Marines in the initial deployment to Haiti. About 200 French troops from Martinique were expected to arrive today.

Abandoned by the United States and other foreign governments, under pressure from relentlessly advancing insurgents, Aristide reportedly signed a letter of resignation before dawn Sunday. Accompanied by his wife, Mildred, and a black-uniformed security detail, he flew into exile at 6:15 a.m. aboard an unmarked white airplane.

State Department spokesman Richard Boucher said the U.S. ''facilitated'' Aristide's departure. Other administration officials said U.S. Ambassador James Foley offered Aristide a secure airplane and found a country that would accept him.

Aristide's destination was to be in the Central African Republic, according to a senior official of the State Department, possibly after a stop in Panama.

SECOND OUSTER

It was the second such humiliation for Aristide, who was ousted by a military coup in 1991 and restored to power in 1994 by 20,000 U.S. troops.

''If my resignation prevents the shedding of blood, I agree to leave,'' Aristide, Haiti's first democratically elected president in 200 years of independence, wrote Sunday.

It didn't work. A new blast of violence rampaged through a capital already fractured and impoverished by turmoil.

Angry crowds of Aristide supporters gathered at the presidential National Palace and roamed elsewhere through Port-au-Prince. Bursts of gunfire reverberated through the streets. Looters plundered banks, police stations and supermarkets. Smoke billowed over the capital.

Neighbors said mobs burned down the homes of Aristide loyalists, including Prime Minister Yvon Neptune and spokesman Mario Dupuy.

Bullet-riddled bodies were seen on city streets. The new death toll could not be determined, but at least 100 people have died in the rebellion that began Feb. 5.

Later Sunday, police finally moved into action -- sometimes in association with rebels -- and the violence subsided.

Alexandre, the new leader and a widely respected figure in Haiti, was sworn in as head of the transitional government. ''I assume [the office] because the constitution indicates it,'' Alexandre said during a news conference.

He urged the eight million residents of Haiti to refrain from further violence.

''The task will not be an easy one,'' he said. ``Haiti is in crisis . .. It needs all its sons and daughters. No one should take justice into their own hands.''

RALLYING CRY

In recent weeks, pro-government militants warned foes that, if Aristide left, they would ''burn down their houses and cut off the heads,'' a rallying cry that founding father Jean-Jacques Dessalines aimed at the French 200 years ago.

Samson Candio, a cook at the Radisson Hotel at Biscayne Boulevard in Miami, became trapped in Haiti following Carnival festivities. On Sunday, he expressed relief that Aristide was no longer in power.

''Look at my country -- it wasn't like this before,'' said Candio, 50. ``He gave guns to kids and put together a fake police. If I saw him, I would slap him.''

Aristide's most outspoken political critics offered few details about their next step.

''Right now we're in the stage of making sure violence doesn't continue and that people put down their guns,'' said Andy Apaid, a spokesman for the political opposition.

U.S. officials, meanwhile, swiftly ordered the Marines into action.

''The mission of the U.S. forces being deployed is to secure key sites in the Haitian capital of Port-au-Prince,'' said Army Col. David McWilliams, a spokesman for the U.S. Southern Command.

Among their duties: ''Helping to create conditions for the anticipated arrival of the U.N. multinational force,'' McWilliams said.

Fifty members of a Marine security team moved into the capital last week to help secure the U.S. Embassy.

JUBILATION

News of Aristide's fall was greeted with glee in the northern city of Cap Haitien, which fell to the rebels last week. Crowds danced in the streets there.

Rebel leader Guy Philippe, who conquered Cap Haitien, said he endorsed the arrival of U.S. and other international troops.

''I think it's a good decision,'' Philippe told CNN. ``The people of Haiti need it and the country needs it. They will be welcome.''

Philippe moved south to Gonaives on Sunday and said he planned to enter Port-au-Prince today.

The rebellion quickly forced government forces to abandon most of northern and central Haiti.

''President Aristide made a decision for the good of the Haitian people,'' Foley, the U.S. ambassador, said during a news conference.

He denied reports that the Bush administration had pressured Aristide to leave, though the White House has been distancing itself from the Haitian president for some time -- an effort that grew more intense in recent days.

First elected president in 1990, Aristide was ousted in 1991 by a military coup but was restored to power three years later. A close associate became president in 1996 and Aristide won reelection in 2000.

But he came under heavy criticism, with opponents charging that he authorized violence against opponents, condoned flawed legislative elections and failed to improve living standards in the hemisphere's poorest nation.

LESS POWER

This time, Aristide was cornered by a rebellion that left him ruling little more than the capital.

As turmoil continues to sweep the nation, hundreds of Haitians have taken to the sea, trying to reach Florida and other havens. Most have been picked up by the U.S. Coast Guard and returned to Haiti.

In Miami, Ira Kurzban, a spokesman for Aristide, said he believed that U.S. intelligence agencies were involved in the ouster.

He noted that one rebel leader, Louis Jodel Chamblain, was a member of FRAPH, a notoriously brutal paramilitary group that supported Haiti's 1991-1994 military dictatorship and was later found to have CIA connections.

''This was a major operation by the intelligence agencies of the U.S.,'' Kurzban said. ``Eventually, the truth will come out.''

Back in Haiti, many people worried about the immediate future: Would the victors and the vanquished find a way to work together or would they engage in a new round of bloodletting?

''It's not easy to talk about the future in Haiti,'' said Jean Francique, the parish priest in the cathedral at Gonaives, birth place of the rebellion.

``But we need soldiers here, from America, to pick up all the guns in the streets first. Then we can begin again.''

Herald staff writers Susannah A. Nesmith in Gonaives, Frank Davies and Warren P. Strobel in Washington, Stewart Stogel at the United Nations and Jacqueline Charles, Andres Oppenheimer, Renato Pérez, Carol Rosenberg and Juan O. Tamayo in Miami contributed to this report.