JOS, Nigeria — Officials say attacks on villages surrounding a central Nigerian city at the heart of unrest between Christians and Muslims have killed more than 50 people this week.

Officials say an assault Wednesday on a village in the Riyom local government area killed 28 people and an attack in the Bokkos local government area killed 18 civilians. On Friday, a military spokesman said at least nine people were killed in the Barkin Ladi local government area.

The fighting often pits Christian villagers against nomadic Muslim cattle-herders.

The attacks around Jos, a city in Nigeria's fertile central belt, come as a string of unsolved killings continue to plague a region that has seen thousands killed in massacres in recent years. Authorities have pleaded for calm over the Easter weekend.