A gang killed three men in Kisauni and Likoni.
According to police and human rights groups, the violence began on Friday and resulted in a police officer being hospitalised with critical injuries.
The worst violence occurred in Likoni on Saturday at around 3.30pm when members of a youth criminal gang called Military descended on residents of Senti Kumi area.
According to Francis Auma who works for Muslims for Human Rights, the group was returning from burying a gang member who had been killed the previous day. The youths attacked residents with knives and machetes.
Mr Auma said one of the men who was killed was identified as 32-year-old Bitunguramye Theobare from Rwanda.
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"After the burial they started attacking the public and the police intervened," said Likoni OCPD Benjamin Rotich, adding that two men identified as Shabaan Hassan and Steve Okoth were slashed.
Police later told The Standard that one of the gang members who was shot and wounded by officers died in hospital.
“Seven criminals were arrested and will be charged today,” said Mr Rotich.
Separately, police on Friday shot and wounded a 28-year-old man in Beersheba area in Kisauni, sparking complaints from his family and activists over what they described as cold-blooded murder by the State.
While police claimed that Ali Athman was a gang member, his family and rights group Haki Africa said that was not a justification to kill or maim suspects.
There were claims that police were enraged by an attack that left an officer in Ganjoni area nursing serious injuries.
Francis Musyoki Syengo was charged with attacking and robbing John Githiri of Sh5,000 using a machete.
Police claimed they shot Athman when he and other gang members attacked officers on patrol, a claim that was disputed by the man's family.