At least eight people were killed in a Haitian slum during a gang feud set off by the weekend murder of a police officer, a U.N. official said.

A former rebel leader who helped topple Haiti's first freely elected president criticized its newest one, accusing President Rene Preval's government of being soft on armed gangs and failing to stem a bloody tide of street violence.

Breaking a long silence, Guy Philippe said efforts by Preval and Prime Minister Jacques Edouard Alexis to negotiate a peace agreement with the gangs has not reduced killings and kidnappings in the capital of Port-au-Prince.

"The Alexis-Preval government hasn't done anything to stop the insecurity," Philippe said in an interview Tuesday with Haitian broadcaster Radio Metropole. "The prime minister is still negotiating with gangs ... and there have been no results."

Philippe's remarks, his first in months, add to growing calls by Haitian legislators and business leaders for a tougher stance against the gangs, which clash frequently with each other, and with U.N. peacekeepers in Port-au-Prince's slums.

The latest to fall appeared to be gang members shot to death between Sunday and Tuesday, U.N. police spokesman Fred Blaze said Wednesday.

The violence in the Martissant slum erupted Sunday after unknown attackers shot and killed an off-duty police officer who had just voted in local and municipal elections.

The officer's killing reignited an ongoing battle between the rival Grand Ravine and Ti Manchet gangs, which are blamed for a wave of shootings and killings in recent months, Blaze said. The link between the officer's death and the gang killings was not immediately clear.

Haitian television showed images Tuesday night of victims laying face down in the street, their arms and legs bound. The bodies of two victims were found burned inside a car.

Barricades of flaming tires went up around the slum Wednesday morning as residents fled, traumatized by three days of shooting, local media reported.

U.N. peacekeepers have increased patrols in the area but were limited in how much they could do, Blaze said.

"Whenever they want to fight, they wait for our patrols to leave and start fighting. That's why it's been so hard" to prevent attacks, he said.

An 8,800-strong U.N. peacekeeping force arrived in Haiti in June 2004 to stabilize the impoverished Caribbean nation.

Philippe, an ex-police chief, was the main leader of a 2004 rebel uprising that ousted former President Jean-Bertrand Aristide. He retreated from the spotlight after losing his bid for the presidency in February elections to Preval, Aristide's former ally.