Kenya's feuding political factions have opened talks aimed at resolving the country's political crisis and ending a month of violence that has killed more than 800 people.

President Mwai Kibaki and opposition leader Raila Odinga attended an opening ceremony in Nairobi Tuesday, with mediator and former U.N. chief Kofi Annan sitting between them.

Mr. Annan said he was confident the immediate political issues could be resolved within four weeks and that broader issues could be solved within a year.

Mr. Odinga said the sides urgently need to address what he called the flawed results of last month's presidential election. Mr. Kibaki did not mention the vote but said he is glad to address underlying issues that caused the violence.

The talks began just hours after gunmen killed a Kenyan opposition lawmaker, Mugabe Were, at his Nairobi home. The killing triggered ethnic clashes in the capital's Kibera slum that killed at least four people, some of them hacked to death with machetes.

In comments earlier Tuesday, Mr. Odinga said the lawmaker's killing was a planned assassination.

Ethnic violence across central and western Kenya has killed scores of people in the last week.

Much of the violence has involved clashes between Mr. Odinga's Luo tribe and the Kikuyu tribe of Mr. Kibaki.

In the city of Naivasha today, three government helicopters opened fire on a crowd that was burning houses and looting shops. The incident occurred as police tried to evacuate about 300 Luos from a country club where they had taken refuge from angry Kikuyus.

Mediators have tried for weeks to forge an agreement between Mr. Kibaki and Mr. Odinga that would bring calm to Kenya.

The opposition accuses Mr. Kibaki of rigging the December 27 vote to ensure his re-election. International observers have said the vote-counting process was flawed.

The president has refused opposition demands to step down or allow a new vote.

Some information for this report was provided by AFP and Reuters.