Gangs armed with machetes and bows and arrows burned and hacked to death members of a rival tribe in the western Kenyan town of Naivasha on Sunday as overwhelmed police stood by helplessly.

At least seven people were killed.The fighting was the latest flashpoint of violence over President Mwai Kibaki's disputed re-election in the U.S.-allied African nation once considered a beacon of stability on the continent.

Groups from Kibaki's Kikuyu tribe set ablaze the homes of Luo rivals in the center of the town, about 55 miles northwest of Nairobi, the capital. Police did not intervene.

An Associated Press reporter counted bodies of seven victims hacked to death or burned alive in their homes.

More than 700 people have died in ethnic violence and clashes with police since Kibaki was declared that winner of Dec. 27 balloting in which observers say the counting was flawed. Some 255,000 people have been forced from their homes.

The eruption of violence in Naivasha appeared to have spread from Nakuru, Kenya's fourth-largest town some 50 miles away, where at least 25 people were killed on Friday.

In Nakuru, rival ethnic groups armed with homemade guns, machetes and bows and arrows fought pitched battles on Friday while mobs torched hundreds of homes.

But Kibaki and opposition leader Raila Odinga, who claims he won the election, remain far apart on how to resolve the crisis, the worst the country has suffered since its 1963 independence from Britain.

Kibaki has said he is open to direct talks with Odinga, but that his position as president is not negotiable. Odinga says Kibaki must step down and new elections are the only way to bring peace.

On Sunday, Odinga was meeting with former U.N. Secretary-General Kofi Annan, the latest international mediator attempting to bring the two sides together.

Opposition spokesman Salim Lone said they were asked to name three negotiators for the talks, which he said he would hopefully start "within a week."

Lone said they expected Annan to deliver four documents Sunday night, three outlining terms of reference and rules of engagement and the fourth an agenda for the talks.

All were drawn up with input from both sides as well as from civil groups. Both sides might want changes to the documents, he said, but "at least now they are moving toward something concrete."

Annan toured trouble spots Saturday in the western Rift Valley, which includes Naivasha, and alluded to underlying causes of the conflict, including decades-old resentment of Kikuyus' domination of politics and the economy, and old grudges over land between different ethnic groups.

"We cannot accept the pattern every five years these sorts of incidents take place and no one is held to account," Annan said. "Let's not kid ourselves this is an electoral problem. This is much broader."

While ethnic clashes have accompanied past Kenyan elections, the scale of the violence this year has been far worse. It has mainly pitted other ethnic groups, which support the opposition because they feel marginalized, against Kibaki's Kikuyu people.

Kikuyus were the main victims in the initial eruption of violence, with hundreds killed and more than half of those driven from their homes belonging to Kibaki's tribe. Now it appears they are on the war path.

The crisis has destroyed the East African nation's image as a peaceful haven in a region rife with conflict.