More than 20 people have died in fresh violence in western Kenya since Friday's agreement by government and opposition on a framework peace plan.
Firemen were unable to save the church in Eldoret
Some were killed by police, others were hacked to death by gangs or shot with poisoned arrows.
A church was burnt down by youths near the Rift Valley town of Eldoret.
The deal between President Mwai Kibaki and opposition leader Raila Odinga aims to end bloodshed in the aftermath of December's disputed elections.
Former UN Secretary General Kofi Annan said the rival parties had agreed a four-point framework for talks which should end the violence within the next two weeks.
But the BBC's Matt Prodger in Nairobi says so far there is little sign that Mr Annan's optimism is having much effect in the streets.
Slums on fire
Further clashes were reported in the western Nyanza province and in Anaimoi, a trading post in the Rift Valley's Kericho district, where opposition MP David Too was shot dead by a policeman on Thursday.
In Kericho itself, mobs set fire to slum dwellings inhabited by members of Mr Kibaki's Kikuyu tribe, Reuters news agency reported.
"Let Annan do his bit but there's going to be no resolution. The clashes will continue," a youth manning a roadblock near the town, who gave his name as Lefty, told the agency.
Near Eldoret, youths set fire to the Great Harvest Evangelical Church. Two people inside at the time are thought to have escaped.
The violence came as Mr Odinga, who leads the Orange Democratic Movement (ODM), responded to Mr Kibaki's suggestion that the opposition should challenge the election result in court.
"Mr Kibaki... is undermining the [peace] process by saying the problems in Kenya can be resolved locally by court action," he said.
Mr Odinga's party has been accused of instigating the violence
The ODM leader says the election was rigged and believes the courts are biased towards Mr Kibaki.
Mr Odinga also denied claims that the ODM had instigated the violence.
"[Kibaki] is trying to cover up the ethnic cleansing that is occurring in his own backyard in central Kenya," he said.