PORT-AU-PRINCE, Haiti - Rebels began patrolling the capital as their leader, Guy Philippe, declared himself military chief and threatened to arrest the prime minister, raising fears of reprisals against supporters of ousted President Jean-Bertrand Aristide.

U.S. Marines, who arrived along with French forces in recent days to secure diplomatic missions and other sites, barely ventured out of the city's airport. Marine Col. Dave Berger said his forces will increase their presence throughout the Caribbean nation following Philippe's comments.

Berger and the commander of the French forces in Haiti - which are the vanguard of an international peacekeeping force - said they have no orders to disarm Haiti's factions and instead were to secure key sites and protect their countries' citizens and government property.

"We are not a police force," Berger said.

Philippe said Neptune - a top member of Aristide's Lavalas party and his former presidential spokesman - would face corruption charges, but the prime minister's whereabouts were unknown. Radio reports said he had been evacuated by helicopter.

Speaking in Washington, Assistant U.S. Secretary of State Roger Noriega said Philippe had no real power.

He is not in control of anything but a ragtag band of people," Noriega told lawmakers Tuesday.

Philippe, who arrived in Port-au-Prince in a rebel convoy on Monday, apparently plans to transform his fighters into a reconstituted Haitian army. The army ousted Aristide in 1991 but then was disbanded by him in 1995, a year after he was returned to power by 20,000 American troops.

Rebels patrolled some streets of the seaside capital. One pointed his assault rifle, finger on the trigger and the safety off, at pedestrians who raised their arms or lifted their shirts to show they were unarmed.

Chile, meanwhile, said it was sending 120 special forces to Haiti on Wednesday, the first of about 300 Chileans to join the international force approved by the U.N. Security Council.

France said it would have some 420 soldiers and police in place by the end of the week. The Pentagon said some 400 Marines would be in Haiti by Tuesday.