One assault occurred at the Church of Christ in Nations in Postikum, in Yobe province. Gunmen attacked worshipers during prayer, killing six people, including the pastor, and setting the building on fire
Worshipers also were attacked at the First Baptist Church in Maiduguri, in Borno state. A deacon and five church members were killed.
They were the latest strikes against Christians in the region. More than 30 people died in a wave of Christmas Day attacks in the north last year, blamed on Boko Haram, a militant group that has targeted Christians and Muslims it considered insufficiently Islamist.