Protestors have clashed with riot police after marching through Haiti's capital to demand officials annul recent elections.
The police responded with tear gas, causing the demonstrators to scatter and blowing stinging gas clouds over a large camp of homeless survivors from the January 12 earthquake.
Between 700 and 1,000 protesters staged their second march in three days in Port-au-Prince to demand the cancellation of the troubled November 28 elections, in which a group of presidential candidates denounced "massive fraud".
"We are here to protest. We want the elections annulled. There were no elections on the 28th," said Charles Baker, one of the presidential candidates denouncing the poll.
The demonstration set off with only about 300 people, but swelled to roughly 700 as it developed. The protest remained peaceful, although some of the candidates leading the march were seen encouraging the energetic crowd to settle down.
Anti-riot police reacted to the protests with tear gas while some protesters burned tyres on the street and threw stones against UN vehicles when the police tried to disperse the march.
The election was riddled with problems. Polls opened late and many registered voters were improperly turned away from polls.
Organisation of American States-Caribbean Community observers also cited instances of violence and voter intimidation, but said the problems were not widespread enough to invalidate the election.