Helicopters open fire above Kenyan crowd

Two Kenyan military helicopters have fired on armed crowds terrorising refugees in the lakeside city of Naivasha as violence in the east African nation threatened to spiral out of control.

Reuters reporters on the scene said the helicopters dive-bombed the crowd several times, firing what police said were rubber bullets at a mob of about 600 people brandishing machetes and threatening members of another tribe. The incident came as police trucks prepared to evacuate about 300 Luo refugees to safety. It was not immediately clear whether anyone was hit.

Earlier, gunmen killed a Kenyan opposition politician at his home in the early hours and ethnic violence continued to spread. Newly elected Orange Democratic Movement (ODM) member of parliament Melitus Were was shot twice in the head as he reached the gate of his house shortly after midnight.

Police called it "murder". But ODM spokesman Tony Gachoka said, without offering evidence, that Were may have been targeted by political foes. "We want no stone unturned in the investigation, but we suspect foul play," he said. Government officials did not immediately comment. Hours after Were's death, rival ethnic gangs began fighting in Nairobi's Kibera slum, not far from where he was shot.

A Reuters witness saw seven corpses, some with cuts on the head and neck. One of them lay in agony on the ground after being forcibly circumcised, before dying.

Unrest also simmered across the volatile Rift Valley, with mobs ransacking homes, burning belongings and threatening people trying to flee Naivasha town, north of the capital. A Reuters witness saw a man hacked to death with machetes.

Around 850 people have been killed since the December vote, which the opposition says was rigged. The violence has taken on a momentum of its own, with cycles of killing between tribes who have never reconciled divisions over land, wealth and power left by British colonial rule and exacerbated by politicians in 44 years of independence.

The turmoil has dented one of Africa's brightest economies -- hotels in a previously booming tourist sector are empty, and the local currency came close to a three-year low today.

Former U.N. head Kofi Annan is spearheading attempts to mediate between Kibaki's government and the opposition led by Raila Odinga. An Annan spokesman said negotiating teams would begin "formal dialogue" on Tuesday afternoon.

Legislator Were was shot soon after midnight as he drove up to his gate in the Woodley district of Nairobi. His attackers fled without taking anything, police said.

Police fired teargas this morning to disperse mourners and supporters, some of whom had taunted officers at Were's house in a middle-class suburb on the edge of Kibera slum.

"There's no justice in Kenya. For whoever killed my husband, God is there," said Wairimu Were, the MP's wife. In Naivasha, about an hour's drive north of Nairobi, crowds ransacked homes and burned belongings of people fleeing the lakeside town, a Reuters witness said. Plumes of smoke rose from different parts, as members of Kibaki's Kikuyu group hunted down Luos, Luhyas and Kalenjins thought to be opposition supporters.

Police opened fire to disperse one mob trying to attack a truck carrying refugees. Nearly 100 people have died in the latest flare-up over recent days in the Rift Valley. Fighting has been largely centred on the towns of Naivasha and Nakuru, better known for their lakes and wildlife, but now deserted by tourists. In horrific images round the Rift, one mother lay in a pool of blood in a Nakuru shack, as her baby cried on a chair nearby. In Naivasha, a man entered a clinic with an arrow in his head.

Protests also rocked the western opposition stronghold town of Kisumu on Monday, residents said. Police fired in the air and one demonstrator died in the morning, residents said. "What is alarming about the last few days is that there are evidently hidden hands organising it now. Militias are appearing ... the targeting is very specific," Britain's Africa Minister Mark Malloch Brown said during a visit to Kenya. Both sides have traded accusations of genocide in a standoff that has shocked world leaders, who had long viewed Kenya as a peacemaker, rather than a problem, on a volatile continent.

About 250,000 people have been displaced by the violence. Official results showed Kibaki narrowly won the Dec. 27 vote, but Odinga says victory was stolen from him by vote-rigging. International observers said the poll was flawed and diplomats are pushing for a power-sharing arrangement.