Former U.N. secretary-general Kofi Annan is in Kenya to begin talks aimed at resolving the bitter political dispute between President Mwai Kibaki and opposition challenger Raila Odinga. Underscoring the urgent need for a solution, opposition supporters and the police clashed again in Nairobi. VOA Correspondent Alisha Ryu has details from Kenya's capital.

Getting the Kenyan political rivals to sit for their first face-to-face talks since the election is the goal of former U.N. Secretary General Kofi Annan, who arrived late Tuesday in Nairobi.

Speaking to reporters at the airport, the former U.N. chief said he and his team of African negotiators did not come to Kenya with an answer to how to stop the unrest, but to assist in finding a solution.

"We are here to insist on a solution for the sake of Kenya and its people and for the sake of Africa," he said. "Our message to the parties is this: There can be no solution without dialogue."

The government says it is open to dialogue but sees no need for international mediation. The opposition says there can be no talks with the government without international mediators.

Meanwhile, in a rare opposition-led gathering permitted by the government.

Thousands of people marched past riot police in a funeral procession for 28 opposition supporters killed last week in clashes with the police in Kibera slum, an opposition stronghold.

The crowd made its way toward a football field for a memorial service attended by ethnic-Luo opposition leader Raila Odinga, who lost to rival ethnic-Kikuyu President Mwai Kibaki in last month's presidential vote that was called unfair by international observers.

In a fiery speech senior opposition party leader, William Ruto, said that although the party is looking for a peaceful settlement of the political crisis through dialogue, he warned the opposition would not stop pressuring Mr. Kibaki to resign and hold a re-run of the vote.

"It is not going to be business as usual. Mwai Kibaki better understand this," said Ruto. "We are very categorical that we will not relent. We will stand firm. We will move forward until justice is done in our country."

In recent days, the opposition has urged Kenyans to boycott businesses owned by politicians and friends close to the president. The opposition has also filed a complaint against the government with the International Criminal Court for crimes against humanity.

The memorial service came to an abrupt end, when police fired tear gas at a group of stone-throwing youths, who blocked traffic and smashed car windows in the street nearby.

Several tear gas canisters landed inside the football field, scattering mourners. Opposition leaders sped away in their vehicles as police battled angry protesters.

A crackdown by Kenyan security forces, enforcing a government ban on political rallies, and brutal ethnic clashes between Kibaki and Odinga supporters have killed hundreds of people and displaced more than a quarter-million others since late December.

At least eight people were reportedly killed overnight in ethnic fighting in Nairobi and in the restive Rift Valley province. The government accuses some opposition leaders, including William Ruto, of orchestrating the ethnic violence, which has largely targeted members of Mr. Kibaki's Kikuyu tribe.