Adding to the chaos, Kenya's electoral commission head Samuel Kivuitu was quoted as saying: "I do not know whether Kibaki won the election." The comment by Kivuitu, who pronounced Kibaki the victor on Sunday, could not be immediately verified.
Western powers have warned their citizens against visiting a popular tourist destination that was regarded as one of the most stable democracies on a volatile continent.
African Union chairman John Kufuor was due in Kenya on Wednesday to try and start mediation, while British Prime Minister Gordon Brown was on the phone to both sides.
"MADNESS"
Pictures of the Eldoret area from air showed plumes of white smoke billowing blazing homesteads. Youths with machetes, rocks and bows and arrows could be seen manning crude checkpoints.
There was early calm in Nairobi slums on Wednesday but residents said Mungiki, a gang with roots in traditional Kikuyu rites, dropped leaflets warning of reprisals against Luos.
In Naivasha town in Kenya's Rift Valley, scores of people were injured in revenge attacks for the church killings, and about 300 terrified locals spent the night camped at a police station and prison for safety.
"We had to seek refuge in the only safe place we know," said Agnes Alouch, in the prison hall.
Kibaki was sworn in on Sunday after official election results showed he had narrowly beaten Odinga. The EU's observer mission said the poll had "fallen short of key international and regional standards for democratic elections".
The United States first congratulated Kibaki, then switched to expressing "concerns about irregularities".
In remarks in the Standard newspaper, Kivuitu said he was pressured by Odinga and Kibaki's party colleagues to announce the poll results immediately. Four members of Kivuitu's team have said they would call for a judicial review.
"I will continue to demand that the fraudulently announced presidential results be rescinded," Raila repeated on Tuesday.
"Until they are, Kenyans will continue to exercise their constitutionally-protected right to stage peaceful protests to rectify this crime."
