President Mwai Kibaki said on Saturday he was ready to form a national unity government to end Kenya's bloody turmoil.

But the opposition brushed the offer aside, saying he must step down and negotiate.

After a week of political violence and tribal clashes since the disputed December 27 election, Kibaki said he would accept a unity government "that would not only unite Kenyans but would also help in the healing and reconciliation process".

But the opposition said the offer changed nothing and only internationally mediated talks would end a crisis that has killed at least 300 people and forced 250,000 from their homes.

"My position has not changed. We want a negotiated settlement. Our starting point is that Kibaki is there illegally. He should not come to the negotiating table as the president," opposition leader Raila Odinga told reporters.

Odinga spokesman Salim Lone told Reuters: "Without international mediation we have no faith that any agreement will be adhered to."

Kibaki's office issued his offer after he met the top US Africa diplomat, Jendayi Frazer. President George W Bush sent Frazer to Nairobi on Friday to try to help end the crisis.

Frazer's mission was the latest attempt at mediation by world powers horrified by the turmoil in what had been seen as one of the continent's most stable democracies, and an ally of the West in its efforts to counter al Qaeda.

Odinga, who had appeared on course to win the vote until Kibaki was handed a narrow victory last Sunday, says the election was rigged and his rival is an illegal president.  - Reuters