Port-au-Prince - Violence between rival groups during Haiti's Senate election left one dead, according to electoral authorities in the troubled Caribbean nation.

The country's top electoral court said late Sunday that one of the leaders of the opposition Fusion of Haitian Democrats in the south-western province of Grand'Anse had been killed.

In other election-related clashes near the capital Port-au-Prince, two other people were injured in Jacmel.

Haitians went to the polls Sunday to fill 11 vacant seats in the 30-member Senate. None of the candidates got an absolute majority in the first round of voting in April.

Beyond the two incidents, however, the authorities stressed that the election had been peaceful in the poorest country in the Americas.

Haitian President Rene Preval said the country's political class should be worried about people's lack of confidence in politics, which translated in a low turnout.

According to Haiti's constitution, a third of the Senate is elected every two years.

Sunday's election was supervised by the UN Stabilization Mission in Haiti (MINUSTAH), a corps that has been helping the country since 2004.(dpa)