Police have fired tear gas to disperse protesters in Haiti who had gathered during a rally marking the 55th birthday of Jean Bertrand Aristide, the former president.

Police had erected barricades at the Champs de Mars, the central plaza in the capital Port-au-Prince on Tuesday, to prevent demonstrators from reaching the national palace, about two blocks away.

But several hundred people stormed through and were repelled by riot police firing tear gas.

The march was also meant to protest against rising food prices, which have increased poverty in Haiti, already the poorest nation in the Western Hemisphere. 

The demonstration began when several hundred Aristide supporters gathered outside the ex-president's former home and swelled to several thousand as they marched across the capital chanting "We need Titid" - Aristide's nickname.

The protest was also aimed to show that Aristide and his Lavalas party are still a political force in Haiti. Five thousand people joined a march marking the fourth anniversary of his removal in February.

Aristide escaped Haiti in 2004 when he was deposed. He now lives in South Africa and accuses the US of staging the coup that ousted him - a charge Washington denies.