A Kenyan Olympic runner who competed internationally for many years was amongst victims of the country's post-poll violence when a mob stoned him to death this week, a close friend said on Friday.

Lucas Sang, a middle-distance runner, had competed in the 1988 Seoul Olympics [Images] as part of Kenya's 4x400 metre relay quartet, and again in the 1992 Games in Barcelona.

Violence has erupted in opposition strongholds in the east African nation over a disputed presidential election that saw President Mwai Kibaki just defeat challenger Raila Odinga, amid accusations of vote-rigging.

A close friend of Sang and also a former professional athlete, Martin Keino, said the runner was attacked on Tuesday night by a stone-throwing gang as he walked with a group of friends. He died when a rock hit his head and the gang then burned his body.

"One of the ways they recognised him was there was a piece of his tracksuit still not burnt on the leg," Keino said. "It's really sad. He was very well known and popular."

Eldoret has seen the worst of ethnic clashes many Kenyans can scarcely believe are happening in their country, usually seen as a relatively stable nation in a turbulent region.

Much of the violence has targeted Kibaki's large, economically dominant Kikuyu ethnic group, especially in Eldoret and the Rift Valley region, where around 90 people have been killed and hundreds of homes burned.

Thousands of people have fled town and around 40,000 in the Rift Valley region are internally displaced, aid workers say

Keino said the rioters mistook the athlete -- who hails from the Kalenjin tribe whose youths have launched many of the attacks in Eldoret -- for a Kikuyu.

"It was at night, in the dark. Tensions are high. They mistook him for someone else, I guess. No one would have done this if they knew it was him. He was so respected."

Lying around 2,000 metres (6,000 feet) above sea level on the western side of Kenya's fork of the Great Rift Valley, Eldoret has produced a series of top athletes.

The most famous, Paul Tergat, held the world record for the marathon from 2003 to 2007, until he was beaten by arch rival Haile Gebrselassie of Ethiopia.

Keino said Tergat was a friend of Sang, but he had not yet managed to contact him to tell him. "He'll be very disappointed, very sad," he said.

A funeral will be held in Eldoret on Saturday. Keino said he hoped it would bring people together. "Hopefully, it's going to make people realise this violence has to stop."