Nigerian police in the northern state of Zamfara on Friday said unidentified gunmen riding on motorcycles shot dead 10 members of the local vigilante group in an attack.

State commissioner of police Usman Gwary disclosed this to reporters in Gusau, the state capital, saying the gunmen apparently came with the specific purpose of killing members of the vigilante group.

Chairman of Zurmi Local Government Area Abdullahi Gurbin-Baure told reporters that the killers came on motorcycles and attacked members of the vigilante killing all the 10 persons on duty.

The chairman said the killers also removed the private parts of some of their victims and burnt all the motorcycles used by the members of the vigilante.

Gurbin-Baure said he had already reported the matter to the state police headquarters and to the state government.