Thousands of opposition supporters marched to Haiti's presidential palace Sunday morning, escorted by heavily armed US marines and French gendarmes, amid fears of clashes with a rival demonstration.
Reporters spotted rebel chief Guy Philippe among the protesters, who witnesses estimated to number as many as 10,000.
Protesters waved banners reading "Never again" and "Peace for Haiti" as they began their protest in the Petion-Ville neighbourhood.
"We demand that Aristide be put on trial, his people also must be tried for looting state coffers and murdering civilians," opposition leader Evans Paul charged.
Several dozen marines and gendarmes, along with Haitian police in riot gear, accompanied the protesters, who marched past Humvees with machine guns mounted on them and armoured trucks trailing along.
Meanwhile, supporters of ex-president Jean-Bertrand Aristide were expected to march from the Cite-Soleil neighbourhood, prompting fears that the rival protests could turn violent in a city already rocked by unrest and chaotic looting following Aristide's resignation and flight one week ago.