NAIROBI - Tensions remained high in a Kenyan slum after a man was killed and 20 houses were torched by rival gangs late Tuesday.

The trouble happened in Nairobi's Mathare 3C area, Wilfred Mbithi, head of police operations in Nairobi, said Wednesday.

Some slum dwellers regrouped after 12 suspects were arrested and torched the shanties, killing a 60-year-old man.

"It was a form of retaliation," Mbithi said, adding that police officers are on the ground looking for the attackers.

Authorities have ruled out any political or tribal causes for the violence that left hundreds of people homeless in the cold weather.

"We have deployed more police officers in the area to help restore calm," Mbithi said.

Nairobi slums, especially Mathare and Kibera, are prone to perennial criminal activity that includes robberies and harassment of residents by gangs.