Nigeria's security agency said on Sunday it had made significant breakthroughs in the fight against Boko Haram and arrested 20 prominent members of the group accused of orchestrating deadly attacks.

President Muhammadu Buhari has made halting Boko Haram's six-year-old insurgency a priority. Boko Haram's six-year-old uprising has left an estimated 20,000 people dead. At least 1,000 people have been killed by the group since Buhari’s election in March.

In the latest violence, 56 people were killed by suspected Boko Haram gunmen at a village in northeastern Borno state on Friday night, Borno state governor Kashim Shettima said late on Saturday during a meeting with the parents of the 219 girls abducted from a school in the region by the extremists last year. Thursday marked 500 days of captivity of the girls from a school in Chibok.

The governor did not provide more details of the attack.

Fleeing residents of Baanu village said they were attacked by Boko Haram on Friday night.

"We returned back to the village in the morning after spending the night in the bush, we saw corpses in the streets of the village," said farmer Mustapha Alibe.

The Department of State Services (DSS) said on Sunday that 20 "notable commanders and frontline members" of the group had been arrested in Lagos, Kano, Plateau, Enugu and Gombe states between July 8 and Aug. 25.

The DSS said it had arrested those suspected of coordinating attacks earlier this year in the northern cities of Potiskum, Kano and Zaria, as well as the central city of Jos, adding that a number of them had made confessions.

"This followed the rounding up of notable commanders and frontline members of the notorious group from different parts of the country," DSS spokesman Tony Opuiyo said in a statement.

The DSS said one of those arrested, Usman Shuaibu, had confessed to leading a team of nine fighters which planned several attacks. Others arrested were accused of ordering attacks, preparing bombs and strapping explosives to suicide bombers.

Wire services