Nigeria - Several people have been killed in a series of bombings by the extremist group Boko Haram that targeted police stations and immigration offices in the northern Nigerian city of Kano.

The attacks were carried out at 5 p.m. local time (1600 GMT) on Friday.

Afterwards, a 24-hour curfew was declared in the city.

No exact death toll has been officially announced so far.

The bombings targeted eight police stations and immigration offices, including a regional police headquarters and the state police headquarters.

Gunfire was also heard in several locations in Kano.

Boko Haram has claimed responsibility for the attacks.

The group said it carried out the attacks in response to Nigerian authorities' refusal to release a number of Boko Haram members arrested in Kano.

In December 2011, Boko Haram claimed responsibility for a series of bombings near the Nigerian capital Abuja. Forty people were killed and many others were injured in the attacks.

The group also carried out a car bombing that killed at least 18 people at the United Nations headquarters in Abuja in August 2011.

HSN/HGL

Source: Press TV