Slain Kenyan human rights lawyer Willie Kimani and a taxi driver have been buried in their hometowns amid calls for top officials to resign over police-linked extra-judicial killings.

Kimani was buried Saturday in his hometown Kabete, while driver Joseph Muiruri was buried in Kinangop in central Kenya.

They were among three men believed to have been killed by police, whose bodies were pulled out of a river just over a week ago. They were abducted on June 23.

The third man, Josephat Mwenda, had sought Kimani's help in pursuing charges against a police officer for shooting him.

Four police officers are facing murder charges in connection with the three deaths.

Isaac Okero, the chairman of Kenya's bar association, has called for the resignation of Kenya's interior minister and police chief.