U.N. Secretary-General Ban Ki-moon touched down in Kenya on Friday for talks with Kenya's opposition leader in a bid to keep the country's post-election chaos from descending into a wider ethnic war.   At least four more people were killed by police during ongoing protests.  Nick Wadhams has the story from Nairobi.

Kenya was tense a day after a second opposition lawmaker was slain within the space of three days. In the western city of Kisumu, which has seen some of the worst violence since Kenya's Dec. 27 vote, police fired on people protesting the death of lawmaker David Too.  Fresh protests also broke out in the Rift Valley town of Eldoret, an opposition stronghold.

Speaking to reporters in Nairobi, Mr. Ban said he was "reasonably encouraged" that Kenyan leaders have the will to solve the crisis, which has killed at least 850 people and displaced more than 250,000. He said the violence has done serious damage to Kenya's economy and its image.

"All international community, the whole world is watching you, the future is on your shoulders," he said.  "I am deeply concerned about this situation, and the number of deaths is just intolerable and unacceptable in this modern world. This must stop, this is up to the Kenyan people. You must act according to all established practices in the modern world."

With President Mwai Kibaki in Addis Ababa for an African Union summit, negotiators from the government and opposition met for the second day to try and break the political deadlock. Opposition leader Raila Odinga has insisted on a new vote to determine the winner of Kenya's presidency, but Mr. Kibaki refuses to negotiate on his victory.  He says Mr. Odinga should take his complaint to court.

Mr. Odinga's Orange Democratic Movement, ODM, insists the December 27 vote was flawed, and many international observers have reported irregularities in the vote count. There have been fears that the violence, initially characterized as an outburst of rage over the conduct of the election, has now devolved into tribal attacks and possibly even ethnic cleansing.

Tensions in Kenya have heightened in recent days with the killings of two lawmakers from Odinga's Orange Democratic Movement.

After his meeting with Mr. Ban, Mr. Odinga insisted that the government accept a U.S. offer for the Federal Bureau of Investigation to help conduct an inquiry into the slaying of Mugabe Were, an ODM lawmaker slain on Tuesday. Mr. Odinga has described Were's killing as a political assassination.

"We are demanding that the government should take up this offer if they really want people to believe that they want to get to the root cause of this matter," he said.  "The police are themselves complicit, police are compromised, they are part of the problem. They cannot be relied upon to carry out an investigation. We want an independent agency to be allowed to carry out this investigation."

Mr. Odinga has also accused the government of playing a role in the slaying of the second lawmaker, David Too. Police have described Too's slaying by a police officer in Eldoret as a crime of passion. Too was killed along with a woman who was the girlfriend of the policeman who gunned them down.