Armed gangs killed 30 people in raids on two villages in an area of northwest Nigeria plagued by cattle rustlers and kidnappers, police said on Sunday.
Dozens of gunmen on motorcycles attacked the villages of Tsauwa and Dankar in Katsina state on Friday, shooting residents and burning homes.
"The bandits killed 21 people in Tsauwa and another nine in nearby Dankar," Katsina police spokesman Gambo Isah said.
"Most of those killed were old people and children who couldn't escape."
Police and soldiers deployed in the area after the attack and arrested one suspect, Isah said.
The attackers burnt homes, livestock and food supplies before fleeing, said Tukur Mu'azu, traditional chief of Batsari, a district the straddles the two attacked villages.
He gave the same death toll as the police for what he described as an "unprovoked attack".
"I have never seen such destruction in my life," the local leader told AFP as he attended the burial of the victims.
Rural communities in Katsina state, the home region of President Muhammadu Buhari, have frequently been targeted by gangs of cattle thieves and kidnappers abducting people for ransom.
The gangs launch attacks from their bases in a vast forest straddling Katsina and several neighbouring states.
Residents across the affected areas have clubbed together to fill the security void by forming self-defence groups, but these vigilante outfits have often served to fuel the violence.
An armed gang on Tuesday burnt to death 21 people, including 16 members of a single family, in a reprisal raid in neighbouring Kaduna state to avenge a vigilante attack on their hideout.