Raila Odinga (file photo)

Unofficial results from Kenya's presidential election show the main challenger, Raila Odinga, holding a significant lead over the incumbent, Mwai Kibaki.

The latest returns broadcast by Kenyan television stations show Mr. Odinga winning between 53 and 59 percent of the votes, with at least half of the ballots counted from Thursday's election.

In parliamentary elections, Kenyan media outlets say at least 10 of Mr. Kibaki's 32 cabinet ministers have lost their seats, including Vice President Moody Awori.

Official results continue to lag well behind those broadcast by the media. The official returns also show Mr. Odinga in the lead, but by a smaller margin.

A spokesman for the opposition Orange Democratic Movement (ODM) has expressed concern at the delay. The chief of Kenya's electoral commission Jack Tumwa said that electoral officials are not "playing any games."

The electoral commission said earlier that vote counting is going more slowly than expected and could continue into Saturday.

Witnesses say voter turnout was high for Thursday's presidential and parliamentary elections, although no figures have been released. International observers say the voting was largely peaceful and free of election fraud.

Mr. Odinga has repeatedly accused Mr. Kibaki of planning to rig the election -- allegations the president has denied.

There were reports of two people being killed Thursday in election-related violence. Police in the western Nyanza district say another person was killed Friday in a dispute at a tallying station.

Kenya's top police officer, Hussein Ali, has urged losing candidates to accept the results peacefully.

About 14 million Kenyans were eligible to vote in Thursday's elections. To win, a presidential candidate must receive a majority of votes and at least 25 percent in five of Kenya's eight provinces. The rule was adopted in 1992 to ensure the president has broad support in a country often divided by tribal issues.

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