South African businessman Cyril Ramaphosa has withdrawn from his planned role as chief mediator in talks to resolve Kenya's political crisis, after the Kenyan government expressed objections. As Derek Kilner reports from Nairobi, former U.N. Secretary General Kofi Annan is currently leading a mediation effort to put an end to violence that as killed about 900 people since a disputed presidential election in late December.

On Friday, representatives of President Mwai Kibaki and opposition leader Raila Odinga agreed on a two-week plan for negotiations toward resolving Kenya's political crisis. Mr. Annan had tapped Cyril Ramaphosa to lead a longer-term negotiation to address underlying issues of contention, including disputes over land and ethnic tensions.

But Ramaphosa announced he is pulling out of the mediation team, after President Kibaki's side expressed opposition to his role.

"I thought that it is best that I should withdraw and go back to South Africa so that I do not become a stumbling block myself," said Ramaphosa. "My experience is that you can only play that role effectively if you have the confidence and full support of those that you are involved with in the mediation process."

Government and opposition representatives resumed discussions, focusing on the humanitarian situation in the country. An estimated 300,000 people have been displaced by violence since the December 27 election.

On Tuesday, negotiators plan to discuss the conduct of the election itself and the role of the Electoral Commission. Supporters of Mr. Odinga claim the vote was rigged, and international observers have said the election was flawed.

The election results set off a wave of violent clashes across Kenya. Much of the violence has fallen along ethnic lines, with members of minority tribes driven out of several communities. Long-running disputes over land are thought to underlie many of the clashes.

Violence continued through the weekend with more than 70 people killed since Friday. The latest clashes have involved members of the Kisii and Kalenjin communities near the town of Kisii in western Kenya.

Mr. Odinga has called for the deployment of international peacekeepers from the African Union or United Nations. Kenya's foreign minister announced that the regional body IGAD would join in efforts to resolve the crisis. But with Kenya currently chairing the group, the opposition may reject the IGAD involvement.