The attack targeted a town hall where Christian Igbo people were holding a meeting, with gunmen chanting “God is great” as they fired Kalashnikov rifles.
The killings come after a spokesman for the sect known as Boko Haram threatened to begin targeting Christians living in the country’s Muslim north in its increasingly bloody sectarian fight with Nigeria’s weak government.
The attack occurred in Mubi in Adamawa state as traders held a meeting before opening up their shops for business, local police commissioner Ade T Shinaba said.
Okey Raymond, 48, who attended the meeting, said: “Everyone scampered for safety, but the gunmen chanted: ‘God is great, God is great’ while shooting.”
No arrests have been made in the attack, which left at least another 15 people wounded.
Friday’s attack comes after gunmen attacked a church in the northeast Nigeria city of Gombe during a prayer service on Thursday night, spraying the congregation with gunfire and killing at least six people including the pastor’s wife.