President Uhuru was declared the winner of the August elections but the Supreme Court ordered the vote annulled.
At least 37 people, including three children, were killed in the protests that followed the announcement of the elections result in Kenya, a local human rights group said.
Some of the deaths were caused by “police using live bullets” while others were killed by police “bludgeoning using clubs”, Kenya National Commission on Human Rights said in a report on Monday.
Among the dead was a six-month-old baby girl who was “clobbered by armed security agents whilst under the care of its mother in Kisumu County”, the report said.
Almost all the victims of the violence were killed in opposition strongholds in the slums of the capital, Nairobi, or the western part of the country.
In August, Fred Matiangi, acting interior minister, denied security services used live bullets or excessive force in dealing with protesters and blamed the violence on “criminal elements”.
“I’m not aware of anyone who has been killed by a live bullet fired by a police officer anywhere in this country,” Matiangi said.
The protests started after the electoral body announced incumbent President Uhuru Kenyatta as the winner of the August 8 election.
Opposition leader Raila Odinga said the election was rigged and claimed he won the vote.
Last month, the country’s Supreme Court declared the election results “invalid, null and void”.
The Nairobi-based court said the electoral board committed “irregularities and illegalities” during the vote, harming the integrity of the election.
Meanwhile, on Monday, hundreds of opposition supporters took to the streets of Nairobi calling for electoral officials to be sacked.
The demonstrators were led by opposition politician James Orengo who said they will not back down in their demands for electoral body reforms.
“We will only participate in an election where we know the outcome will be free and fair,” Orengo told the opposition supporters.
Last week, security forces fired tear gas to disperse the protesters.
Rallies were also reported in several other cities.
Odinga has vowed not to participate in the October 26 presidential election rerun if opposition demands for an election commission overhaul are not met.