Kenyan politician Raila Odinga rejected as a "travesty" the result of the Aug. 9 presidential election he was declared to have lost to Deputy President William Ruto and warned on Tuesday of a long legal crisis facing Kenya's democracy.

His first comments on the result came after four of the seven election commissioners said they stood by their decision a day earlier to disown figures announced by electoral commission chairman Wafula Chebukati.

The dramatic series of events has raised fears of violence similar to what followed disputed polls in East Africa's richest country in 2007 when more than 1,200 people were killed and again in 2017 when more than 100 people died.

Overnight, Odinga's supporters battled police and burned tyres in the western city of Kisumu and the capital Nairobi's huge Kibera slum, but calm had returned to the streets by Tuesday morning.

"Our view is that the figures announced by Chebukati are null and void and must be quashed by a court of law," said Odinga, a veteran opposition leader and five-time presidential candidate who was backed this time by outgoing President Uhuru Kenyatta.

"What we saw yesterday was a travesty," he told reporters, but appealed to his supporters to remain peaceful. "Let no one take the law into their own hands," he said.