An accidental explosion on an oil pipeline In Nigeria operated by Italian energy giant Eni left 12 people dead and three injured, the company said in a statement Friday.

The explosion happened on Thursday during repair work on the pipeline, which had been damaged by acts of sabotage, Eni said, adding that the circumstances of the accident were still not clear.

Hundreds of members of a campaign group calling for the release of 219 schoolgirls kidnapped by Boko Haram marched on Nigeria's presidential villa on Wednesday to demand government action.

The BringBackOurGirls movement has held marches and demonstrations virtually every day since the teenagers were seized from the Borno state town of Chibok, northeast Nigeria, on April 14, 2014.

The death toll in a twin attack on the central Nigerian city of Jos has risen to 51, the country's National Emergency Management Agency said on Wednesday.

"As at yesterday (Tuesday), it was 51," said NEMA coordinator for Jos, Mohammed Abdulsalam.

A female suicide bomber on Tuesday blew herself up near a military checkpoint in restive Nigeria's northeastern Borno state, killing four people, witnesses said.

"The woman ... alighted near a military check point in Sabon Gari where she blew herself up and killed four other people," witness Maikaho Abdu told AFP.

At least 25 people were killed when a bomb blast ripped through a packed government office in Zaria, northern Nigeria, on Tuesday, in a suspected suicide attack likely to be blamed on Boko Haram.

The explosion occurred at about 9:00 am (0800 GMT), as primary school teachers and public sector workers were queuing for identity checks, according to witnesses.

Gunmen suspected of being cattle thieves killed at least 37 people in a village in northern Nigeria's Zamfara state, a local government official said Monday.

"The gunmen killed 37 people in the attack on Cigama village shortly after they attacked Kokeya village where they killed two people," Muhammad Bala Gusami told AFP after Saturday's violence.

At least 44 people were killed in twin bomb blasts in the central Nigerian city of Jos, the emergency services said on Monday, after a wave of mass casualty attacks blamed on Boko Haram militants.

Sunday's bombings took the death toll from raids, explosions and suicide attacks to 267 this month alone and to 524 since Muhammadu Buhari became president on May 29, according to an AFP count.

A suicide bomber blew himself up on Sunday inside a church in the restive northeastern Nigerian city of Potiskum, killing five worshipers in the latest in a series of attacks, a police officer and witness told AFP. 

The bomber entered the Redeemed Christian Church of God at 9:55 am in the Jigawa area on the outskirts of the city and detonated his explosives. 

Several female suicide bombers blew themselves up amid panicked villagers fleeing a Boko Haram attack in a northeast Nigeria killing scores, the army and witnesses said Saturday.

The latest carnage in series of attacks that have claimed more than 200 lives in just three days happened on Friday night in Zabarmari village, 10 kilometers (six miles) from the city of Maiduguri, the birthplace of the jihadist group.

Suspected Boko Haram militants killed 11 men overnight Friday in northeastern Nigeria, dragging them from their homes and shooting them for escaping forced conscription by their group, residents said.

"Boko Haram fighters killed 11 people in our village (Miringa) this morning. The men had fled Gwargware village in (neighboring) Yobe state to seek refuge in our village after Boko Haram tried to force them to join their ranks," said resident Isa Mshelia.