Nineteen people were killed and at least 23 injured in the latest suicide attacks in Nigeria's northeast region, local police said on Wednesday.

Borno State police chief Damian Chukwu told reporters here the multiple deadly attacks in the state's Maiduguri city late Tuesday targeted a civilian self-defense force.

Among the deceased, 12 were members of the civilian self-defense force, Chukwu said. The seven other victims were un-armed civilians or passersby.

Four female suicide bombers carried out the attacks in three different areas of the troubled northern Nigeria city.

The local police suspected that the attacks were carried out by terror group Boko Haram.

The group had attempted to infiltrate Maiduguri, the Borno State capital after they were chased out of the city.

Boko Haram has been blamed for the deaths of more than 20,000 people and displacing of 2.3 million others in Nigeria since their insurgency started in 2009.

At least 860 members of the civilian self-defense force, assisting the military in fighting Boko Haram, have been killed since 2014, according to data by the police.

Nigerian government forces are intensifying land and aerial surveillance to flush out the terror group from their hideouts in the northeast region.

source: Xinhua