Gunmen have killed at least 20 people in northeastern Nigeria, the latest in a series of deadly attacks in the region.
The attacks on Christians Friday happened in the Mubi district of Adamawa state, near the border with Cameroon. A local journalist told VOA Hausa service that unidentified gunmen opened fire at three locations in the district.
Reports from the area say the attacks targeted people of the Igbo ethnic group.
A purported spokesman for the radical Islamist sect Boko Haram claimed responsibility for the attacks in a phone conference with journalists.
The spokesman, known as Abu Qaqa, also said Boko Haram was responsible for an attack on a church in Gombe state late Thursday that killed six people and wounded 10.
He said the attacks were in response to an ultimatum Boko Haram issued earlier this week, demanding that Christians in the largely Muslim north leave the region.
Boko Haram has claimed responsibility for a number of recent attacks in Nigeria, including the Christmas day bombings that killed more than 40 Christians.
The sect, whose name means "Western education is a sin" in the Hausa language, has been blamed for dozens of deadly shootings and bombings mostly in the country's north.
It is fighting to implement a radical interpretation of Islamic law across Nigeria, which is divided between a primarily Muslim north and a mainly Christian south.
Nigerian President Goodluck Jonathan declared a state of emergency in 15 regions last week, closing parts of the borders with Niger, Chad, and Cameroon. Mr. Jonathan has vowed to crush Boko Haram, but his critics complain that he has done little to rein in the group.