Gunshots and an explosion have been heard at a teacher training college in the northern Nigerian city of Kano.
Students were seen fleeing from the city's Federal College of Education.
There was no immediate indication of whether there had been any casualties in the attack.
Nor was it clear who was responsible for the attack, although suspicion will fall on militant Islamist group Boko Haram, which has been waging an insurgency in Nigeria since 2009.
This page will be updated as more comes in:
http://www.bbc.co.uk/news/world-africa-29244107
