BY NANCY SAN MARTIN, SUSANNAH A. NESMITH AND MARTIN MERZER

PORT-AU-PRINCE -- Bodies lay in streets, thugs robbed motorists at gunpoint and thousands of looters plundered warehouses Friday as anarchy roiled Haiti's capital.

Rebels called it the last gasps of President Jean-Bertrand Aristide's regime. They seized two more objectives -- Les Cayes, Haiti's third-largest city, and Mirebalais, a strategic town just 25 miles from Port-au-Prince.

At least a dozen bodies were strewn on the capital's streets, some shot in the head. Armed Aristide loyalists hijacked cars and stripped motorists of valuables. Looters descended on the port, fighting with each other, carrying away food and appliances.

Once again, the international community deplored the disorder in Haiti but took no concrete steps to stop it.

In Miami, U.S. military officials mapped plans for a possible mission to Haiti but emphasized that no troops had been mobilized or ships diverted.

In Washington, Bush administration officials raised the diplomatic pressure, privately urging Aristide to resign and ''stop a bloodbath in the streets of Port-au-Prince,'' according to a senior administration official.

But Haiti's embattled president remained in office, surrounded by the two million residents of a rapidly unraveling city and eight million residents of a country largely without a central government.

''I have the responsibility as an elected president to stay where I am, protecting the people the way I am, the way I can,'' Aristide told CNN.

GRIM SITUATION

Meanwhile, something very close to chaos reigned Friday in Port-au-Prince. Few, if any, police officers were seen on the streets throughout the day.

''You see what it's like here? Life is very hard,'' one young man said as he watched blood drain from the bodies of two corpses dumped in the middle-class Branrico neighborhood.

Both victims had been shot in the head. Two unused shotgun shells remained on the ground, one next to each body, as if to send a message. One of the dead men had his hands tied behind him.

Though rebels moved closer, they were not visible Friday in Port-au-Prince, and most observers believed that the deaths -- apparently revenge killings -- were the work of militant Aristide supporters called chimres, after a mythical dragon.

The senior Bush administration official, who requested anonymity, said the White House believes that Aristide may have given the order to begin killing opponents and looting businesses.

Rebel leader Guy Philippe threatened to blockade Port-au-Prince's port, take other towns around the capital and tighten the noose around the remnants of Aristide's government.

In effect, Philippe seemed to suggest a siege rather than an immediate and direct attack. Moving swiftly since the rebellion began Feb. 5, insurgents have ousted the government from nearly all of northern and central Haiti.

''We're going to block Port-au-Prince,'' Philippe told The Herald in Cap Haitien, Haiti's second largest city. ``We're going to send two boats so the big boats coming from Miami with gas or with food will come to Cap [Haitien].

``No more boats to Port-au-Prince. What we want is desperation first, so that's what we're doing now -- closing the circle.''

More than 80 people have been killed and dozens wounded in the rebellion. Hundreds of Haitians have taken to the sea, many of them intercepted and repatriated by the U.S. Coast Guard.

On Friday, 531 Haitians were delivered by the Coast Guard to the capital's port, not far from where looters ran amok. A U.N. official in Cuba said the island has built a camp for potential Haitian refugees.

Thousands of men, women and children carried away anything they could. Fights erupted. One teenager tried to stab another with a kitchen knife to steal goods previously stolen from ripped-open containers.

Armed men stationed at the port's entry gate demanded tribute from looters. ''What do you have for me?'' they asked before allowing looters to leave.

One of the warehouses reportedly belonged to Olivier Nadal, a businessman now in exile and known as an Aristide opponent.

Elsewhere in the city, businesses closed. Motorists, including some foreign journalists, were stopped at gunpoint and had their vehicles stolen.

'CRIME EVERYWHERE'

''We stay inside our homes all day,'' said Margarite Antoine, a mother of three. ``We have no other choice. There is crime everywhere. I'm always scared.''

In Washington, White House spokesman Scott McClellan said the United States still seeks a solution between Aristide and his political opponents, who have distanced themselves from the armed rebels.

McClellan did not expressly call for Aristide's exit. Secretary of State Colin Powell expressed doubt Thursday about Aristide's ability to remain in office.

''Obviously we continue to have concern for the Haitian people,'' McClellan said.

Several Caribbean nations and France said they were considering contributing police to a multinational force under the umbrella of the United Nations. The United States and France officially say they would participate only after a political settlement in Haiti, although Paris is far more eager to intervene.

In South Florida, U.S. military planners studied several scenarios at Miami's Southern Command, headquarters for U.S. military operations in Latin America and the Caribbean.

''There is no mobilization, no alert, nothing official,'' said Southcom spokesman Raul Duany. ``We're just looking at every course of action.''

Frustrated by what they termed White House inaction, Florida Democratic Sen. Bob Graham and two other senators -- Tom Harkin, D-Ia., and Chris Dodd, D-Conn. -- renewed their call for swift intervention by a multinational police force.

Graham said that either way, whether Aristide survives or rebel groups prevail, ``there is great potential for a rage of revenge by the victors over the vanquished.''

Human rights activists also expressed alarm, saying that Aristide, Philippe and other leaders on both sides have been associated with abuses in the past.

''Given the past atrocities of some rebel leaders and the violent propensities of pro-government gangs, we're gravely concerned for the the protection of the Haitian population,'' said Joanne Mariner, deputy director of Human Rights Watch's America's division.

Herald staff writers Trenton Daniel and Carl P. Juste in Port-au-Prince, Frank Davies and Joseph L. Galloway in Washington, and Jacqueline Charles and Carol Rosenberg in Miami contributed to this report.