Suspected Islamist fighters have killed 10 Christians in an overnight machete and gun attack in Borno state in north-east Nigeria.
Later, gunmen attacked government targets and churches near the border with Cameroon, killing five policemen.
It is not yet clear who was behind the attacks.
But the army suspects the Islamist Boko Haram group, which often targets security forces, government officials or Christians it views as infidels.
Late on Saturday night, residents say a group of men went from house to house in a largely Christian area of the remote village of Chibok, before slitting the throats of 10 people.