At least 13 people have been killed after gunmen have attacked a teacher training college in the Nigerian city of Kano, officials said.

Students were seen fleeing from the city’s Federal College of Education and at least one explosion was heard.

Another 34 people were injured.

It is not clear who was responsible, although suspicion will fall on militant Islamist group Boko Haram, which has been waging an insurgency in Nigeria since 2009.

In July 2014, Kano suffered a spate of five attacks in four days, one of which also targeted a college and killed six people.

In July 2014, Kano suffered a spate of five attacks in four days, one of which also targeted a college and killed six people (photo Reuters)

In May 2013, Nigeria’s President Goodluck Jonathan imposed a state of emergency in the northern states of Borno, Yobe and Adamawa, vowing to crush the insurgency.

However, the militants have stepped up attacks, killing more than 2,000 civilians this year, according to New York-based Human Rights Watch.

Boko Haram’s name translates as “Western education is forbidden”, and it has carried out several attacks on schools and colleges, seeing them as a symbol of Western culture.

In April, Boko Haram raided a boarding school in Chibok town in the northern state of Borno, and is holding more than 200 girls that its gunmen abducted during that attack.