Article published on the 2009-04-20 Latest update 2009-04-20 13:00 TU
Armed men clashed with UN and local security forces in the northern town of Marchand Dessalines, with one soldier wounded, according to election officials.
In other parts of the country polling stations were closed because hundreds of protesters demonstrated outside them.
Famni Lavalas called for the boycott after all 17 of their candidates were among the 40 banned from standing, reportedly because of procedural irregularities. The holding of the election has been dubbed "contentious" by international campaigners.
Haitian President René Preval declared earlier in the week that "stability is still fragile and needs reinforcement", saying that drug trafficking undermines democracy and the rule of law.
On a brief visit on Thursday, US Secretary of State Hillary Clinton said she was "encouraged" by pledges of 324 million dollars (250 million euros) at an international donors' conference in Washington on Tuesday. She said that the US will give Haiti 57 million dollars (44 million euros) as part of the package.