Kenyan motorcycle taxi drivers burned a police post as thousands demonstrated across the country against extra-judicial killings linked to the police that human rights activists say is pervasive.

Hundreds of lawyers from the Law Society of Kenya on Wednesday marched to police headquarters to demand action against murders linked to the police.

The protests have been sparked of by the murder of human rights lawyer Willie Kimani, his client, motorcycle taxi driver Josephat Mwenda, and taxi driver Joseph Muiruri. The three went missing on June 23 and their bodies were pulled from a river Friday.

Mwenda had reported to authorities that a police officer at the Syokimau police post had shot him in an unprovoked incident on April 2015.

Four police officers are being held for the deaths.