BY NANCY SAN MARTIN AND SUSANNAH A. NESMITH

PORT-AU-PRINCE -- After a stiff U.S. warning and just ahead of the first Marines to roll through this city, rebels left the Haitian capital Wednesday and said they would turn in their weapons -- a clear advance for U.S.-led peacekeepers.

But the Caribbean Community said it would not participate in the multinational security force and called for an independent investigation into former Haitian President Jean-Bertrand Aristide's allegation that he was ``kidnapped.''

Meeting in Jamaica, CARICOM leaders said that Haiti was too chaotic for the 15-member regional bloc to become involved in the U.S.-led multinational security force but that it would provide humanitarian assistance.

The decision came after they spoke with Aristide by phone and heard his allegation that U.S. agents forced him to resign and fly into exile in the Central African Republic. Washington has vehemently denied the charge.

''Several of us were in touch with [Aristide] . . . until very late Saturday night,'' said Jamaican Prime Minister and CARICOM Chairman P.J. Patterson. ``Nothing that was said to us indicated that the president was contemplating a resignation.''

At a news conference in Port-au-Prince one day after he declared himself Haiti's ''military commander,'' rebel leader Guy Philippe announced that he was disarming his fighters and returning to Cap Haitien, the northern port city where he once served as police chief.

Although Philippe was wearing combat fatigues, the few rebels around him at the Hotel Ibo Lele were dressed in civilian clothes and were unarmed -- a stark contrast to previous days when the men swaggered around the city with M-16s and other assault weapons.

REBEL DECISION

''Now that there are foreign troops promising to protect the Haitian people . . . we will lay down our arms,'' said the normally flamboyant, now subdued Philippe.

Earlier in the day, Philippe told The Herald: ``We can't fight here. The U.S. asked us to lay down our weapons.''

And it wasn't just anyone asking. Marine Col. Charles M. Gurganis, commander of the U.S. forces in Haiti, confirmed that he had met with Philippe early Wednesday.

''We had a polite and very short meeting, and I asked him to honor what he said he would do -- disarm his men,'' Gurganis said. He added that the rebels were not told to leave the capital. A U.S. official said ''no deals'' were offered.

The politeness was reinforced with muscle later in the day as U.S. Marines in armored vehicles rolled through parts of downtown Port-au-Prince for the first time since they began arriving on Sunday. One of their spokesmen called it a ''reconnaissance'' rather than a patrol.

The international security force now totals about 850 U.S. soldiers, 500 French police and troops, and about 60 Canadians. Chile has promised about 300 army troops, and the force is expected to grow to up to 5,000 members in coming weeks.

Interim President Boniface Alexandre, meanwhile, moved into the National Palace and announced on radio that he would serve for only three months. Alexandre, the former chief justice of the Supreme Court, also appealed for everyone -- rebels, armed pro-Aristide gangs and other citizens -- to surrender weapons.

''This has to happen immediately,'' he said. ``We have no time to lose. Right now, Haitians have a new force. We've got to put aside our hate and build a nation.''

SHOW OF FORCE

But it was clear by midday that the only real power in Haiti right now is the international security force.

In a show of force, Marines traveling in a convoy of 10 Humvees and armored cars spread out across 30 blocks near the National Palace as others on foot cleared the streets of torched cars that had served as makeshift barricades.

Troops also provided security at the airport for the first shipments of humanitarian aid to arrive since the revolt that began Feb. 5, left more than 100 dead, paralyzed aid deliveries and forced Aristide to resign last weekend.

Witnesses said at least five busloads of Haitians affiliated with Aristide's Lavalas Family party were escorted to the airport Tuesday by armed security men and put aboard a departing charter flight.

''The American Embassy came with four or five buses,'' said Felix Sidney, a 34-year-old airport baggage handler. He said he recognized several Aristide supporters, including a popular musician known as ``K.C.''

PASSENGERS NAMED

Others were identified as René Civil and Paul Raymond, two prominent hard-liners. Raymond, head of the pro-Aristide Little Community Church party, threatened opposition leaders and local journalists in 2001 by saying that he would turn their skulls into inkwells and their skin into parchment, and use their blood as ink if they didn't back off.

In Washington, U.S. officials said a charter had carried out U.S. citizens, Haitian Americans and Haitians, but declined to confirm that they included Aristide supporters.

Elsewhere in the capital, an intense but brief firefight broke out Wednesday in the La Saline shantytown, known as a redoubt of pro-Aristide gunmen called chimres. It was not immediately clear who was involved in the shooting.

In the port of St. Marc, a two-hour drive north of the capital, looters ransacked the seaport and attacked a radio station, according to radio reports. Five people were reported killed.

At the Port-au-Prince city morgue, a hospital worker said 30 bodies had been brought in since Sunday, The Associated Press reported.

CONCERN OVER DELAYS

Leaders of the anti-Aristide opposition said they were glad the rebels had agreed to disarm, but they complained about the delays in forging a transitional government that have left Haiti's security in the hands of rebels, chimres and criminals.

CARICOM's decision Wednesday was a further blow to efforts to use the regional bloc's January plan for a transition government as the basis for ongoing efforts to forge a new Haitian government.

Prime Minister Yvon Neptune, who served under Aristide, is moving too slowly on a ''process that is urgent,'' opposition spokesman Andy Apaid said.

Staff writers Joe Mozingo and Trenton Daniel and special correspondent Stewart Stogel contributed to this report.