Kenyan police on Wednesday said they killed two protesters and wounded several others, including one seriously, in clashes with opposition supporters in the western city of Kisumu.
"One man was shot in the back as police were trying to disperse about 1,000 youths who were trying to gather here," a police commander who requested anonymity told AFP.
The same commander later said a second man had died of gunshot wounds in hospital.
He could not give the exact number of injured but said at least two men had been hospitalised.
Hundreds of paramilitary police earlier battled angry youths in the city's slums and outskirts in a bid to block them from the main park for a protest rally.
Kenya's Orange democratic movement launched the nationwide rallies in a fresh challenge to President Mwai Kibaki's widely contested re-election.
Opposition leader Raila Odinga claims he was robbed of the presidency in the December 27 polls, which sparked a week of riots,police raids and tribal violence, and left more than 700 people dead.