A suicide bomber drove a car full of explosives into a church in northern Nigeria, killing at least 12 people.

Security forces at a road block nearby said the bomber forced his car through the checkpoint and drove into the church in Yalwa, on the outskirts of the city of Bauchi.

It was not clear who was responsible for the attack. 

Churches have been targeted by militant Islamist group Boko Haram this year - who are increasingly using suicide bombers.

The group have been blamed for hundreds of killings in bomb or gun attacks over the past two years.