Boko Haram militants killed 56 people in a remote village in Nigeria's Borno State, the governor of the region said Sunday. News of the latest attack came the same day as an announcement by Nigeria's security agency about the arrest of 20 prominent members of the Islamic extremist group.

The attack in Baanu village was confirmed by Gov. Kashim Shettima during a meeting with parents of over 200 girls who were abducted from a school in the region by the extremists in April 2014. Thursday marked 500 days of captivity of the girls from a school in Chibok.

"I want us all to understand that the Boko Haram crisis is a calamity that has befallen us, as the insurgents do not discriminate whether somebody is Christian or Muslim, neither do they have any tribal sympathy or affiliations,” Shettima said, according to the Associated Press. “Just yesterday they killed 56 people in Baanu village of Nganzai local government, as I am speaking to you their corpses are still littered on the street of the village because virtually everyone in the village had to run for their lives.”

The governor reportedly did not provide details of the latest attack, but residents of Baanu village said they were attacked 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," a farmer, identified as Mustapha Alibe, reportedly said.

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

The DSS reportedly said that one of those arrested -- identified as Usman Shuaibu -- had confessed to leading a team of nine militants who planned several attacks.

Boko Haram, which aims to establish an ISIS-style government in northern Nigeria, has killed thousands of people since launching a brutal insurgency in the country six years ago.

Nigeria's President Muhammadu Buhari has given the country’s military three months to end the Islamist group’s violence. Under his leadership, Boko Haram has faced considerable setbacks and has been driven out of nearly 25 towns, but has in response escalated its retaliatory attacks. The group is believed to have killed about 1,000 people since Buhari was elected in April this year.