An explosion has hit a crowded shopping centre in Nigeria’s capital Abuja, killing at least eight people, witnesses say.

Wednesday’s latest explosion occured just two days after police blamed Boko Haram for a blast that struck a medical college in the northern Nigerian city of Kano, killing at least eight people and wounding 12 others.

“We received the information at about 1500 GMT about a blast” on Wednesday at the Emab Plaza, not far from the seat of government, Manzo Ezekiel, spokesman for the National Emergency Management Agency (NEMA), said.

“Rescue operation has already commenced.”

It was not clear what caused the blast but the armed group Boko Haram has attacked Abuja twice in the last 10 weeks, including a car bombing in April that killed 75 people at the Nyanya bus terminal on the city’s outskirts, while a copycat bombing at the same spot on May 1 left 19 people dead.

A teacher at the college told AFP that the blast seemed to originate from a car park next to the post-secondary training school.

Boko Haram, which aims to create a state in northern Nigeria ruled by Islamic law, did not immediately claim responsibility but the school matched its target of Western education.

The armed group, which has attracted international condemnation since April when it kidnapped more than 200 schoolgirls who remain captive, has also been blamed for abducting 60 girls and women and 31 boys from villages in northeast Nigeria over a three day period – Thursday, Friday and Saturday.

On Saturday, scores of Boko Haram fighters attacked four other villages close to Chibok, in Borno state, near the Cameroon border, from where hundreds of girls were kidnapped in April.

Witnesses said at least 33 villagers were killed as well as six vigilantes and about two dozen Boko Haram fighters.

Nigeria’s government has not succeeded in curbing the armed group’s violence.