The latest victim was shot dead by police in the Kawangware slum in Nairobi during clashes involving members of three tribal groups, police and witnesses said.
"We have one fatality -- a person shot during the skirmishes. The situation is still tense because the area is dark after the power went off," a police officer at the scene told AFP, speaking on condition of anonymity.
Nairobi Police Chief Japheth Koome confirmed the death but gave no further details.
"That's when an all-out war broke out and youths armed themselves to protect businesses.. because there was looting by some who took advantage," he said, noting that a supermarket was broken into then set on fire.
More From This Section
When the polisce turned up, the youths fled but continued to hurl stone at each other and at the police, who opened fire, killing one, he told AFP saying there were "gunshots all over".
A witness said the man had been shot as people "were running away from the police" but the local police chief said the man had been shot after trying to grab an officer's gun.
Another six people died in yesterday's violence, most of them in Odinga's western strongholds.
Since independence in 1963, three of Kenya's four presidents have come from the Kikuyu ethnic group, to which President Uhuru Kenyatta belongs. The other was Kalenjin.