Haiti's interim president took the reins of his country's shattered government Monday as supporters of Jean-Bertrand Aristide (search) demanded the ousted leader's return. U.S. Marines acknowledged they killed one of seven people gunned down in weekend violence — the first armed action of their week-old mission here.

Military helicopters circled overhead and U.S. Marines in armored cars patrolled the streets Monday outside the National Palace as Boniface Alexandre (search) was formally installed.

"Aristide or death!" Aristide supporters yelled at the gates of the palace during the ceremony, their shouts carrying into the room where Alexandre urged his countrymen to remain calm.

"We are all brothers and sisters," said Alexandre, who has served as president for a week and was officially sworn in Feb. 29. "We are all in the same boat, and if it sinks, it sinks with all of us."

Earlier, Aristide declared from his African exile that he was still president of Haiti and urged "peaceful resistance" in his homeland.

"I am the democratically elected president and I remain so. I plead for the restoration of democracy," Aristide said from Bangui, Central African Republic, in his first public appearance since he fled Haiti Feb. 29 aboard a plane chartered by the U.S. government.

Aristide said his departure was a "political kidnapping (that) unfortunately opened the road to an occupation."

The United States denies Aristide's charge that he was forced to step down. But the 15-nation Caribbean Community has called for an international investigation.

In Washington, State Department spokesman Richard Boucher said, "If Mr. Aristide really wants to serve his country, he really has to, we think, let his nation get on with the future and not try to stir up the past again."

Aristide was a wildly popular slum priest, elected on promises to champion the poor who make up the vast majority of Haiti's 8 million people. But he has lost support, with Haitians saying he failed to improve their lives, condoned corruption and used police and armed supporters to attack his political opponents.

U.S. Marines and French Legionnaires have been in Haiti since Aristide's departure Feb. 29, the vanguard of a U.N. force to restore peace to the country, where a monthlong rebellion left more than 130 dead. On Monday, there were about 1,600 Marines, 800 French soldiers and police and 130 Chilean troops in Haiti.

A United Nations team was on its way to Haiti to plan for a multinational force that will deploy there within the next three months, a U.N. spokesman said Monday.

On Monday, hundreds of people ransacked Port-au-Prince's industrial park, carrying away wood paneling, toilets, even a plastic Mickey Mouse. One looter wore the top part of horse costume on his head as he made off with a mirror. The looting took place less than half a mile from the international airport where U.S. Marines have set up base.

Alexandre urged people "to keep calm. No one has the right to do justice by themselves."

Monday's pro-Aristide demonstration was mostly peaceful, a sharp contrast to the massive anti-Aristide protest Sunday in which seven people were killed, including a foreign journalist.

U.S. Marines acknowledged Monday they killed one gunman at Sunday's demonstration. "He had a gun and he was shooting at Marines," Col. Charles Gurganus told reporters Monday.

Gurganus said they did not know who the man was, did not know where his body is, and did not have his weapon, which he said was snatched by someone.

The violence, the worst bloodshed since Aristide fled, led both opponents and supporters of Aristide to threaten armed action, damaging efforts to reach a frail peace.

Chief rebel leader Guy Philippe (search) said Sunday's attack never would have happened if his men had not been asked to lay down their arms. He warned Monday that "I will reunite my men and take up arms" if the peacekeepers did not disarm Aristide loyalists blamed for Sunday's attack.

Later, Philippe met with opposition leader Evans Paul, with whom he has wanted to discuss reconstituting Haiti's disgraced army, whose brutality and corruption is blamed for keeping Haiti in misery.

Ignoring Aristide's claims to Haiti's leadership, a recently appointed seven-member Council of Sages was interviewing three top candidates for prime minister Monday, to replace Aristide appointee Yvon Neptune (search).

The new premier, whom the council hoped to name on Tuesday, would form a transitional government from Aristide's Lavalas party and a disparate opposition coalition.

The candidates are:

— Businessman Smarck Michel, Aristide's prime minister in 1994-1995 who resigned over differences in economic policy.

— Retired Lt. Gen. Herard Abraham, who is probably the only Haitian army officer to voluntarily surrender power to a civilian, in 1990. He allowed the transition that led to Haiti's first free elections in December 1990, which Aristide won in a landslide.

— Gerard Latortue, a former U.N. official and an international business consultant who was foreign minister in 1988 to former President Leslie Manigat. Manigat was toppled in one of the 32 coups fomented by Haiti's army, which ousted Aristide in 1991 and was disbanded after 20,000 troops came to Haiti in 1994 to halt an exodus of boat people to Florida and restore democracy.