MAIDUGURI, Nigeria –  Residents of a northwestern Nigerian village say suspected sect members disguised as traders invaded a market and opened fire, killing at least 15 people.

Ngubdo Modu said Thursday gunmen also set fire to the local government secretariat, police station and a clinic during the attack Wednesday in Gajiram, 75 kilometers (46 miles) from Maiduguri, the volatile capital city of Borno state where the Boko Haram ideology sprang up some four years ago.

Modu said that the attacks may have been in retaliation for recent arrests of sect members identified by a local vigilante group.

The state attorney-general and the state police commissioner are visiting Gajiram to give condolences to the families of those killed and to ascertain the extent of the damage.