Gunmen killed 47 people in attacks on villages in north-western Nigerian state Katsina on Saturday, local police said.
“Armed bandits”, some wielding AK-47s, carried out the attacks, Katsina police said in a statement.
Hundreds were killed last year by criminal gangs carrying out robberies and kidnappings in north-west Nigeria.
Attacks add to security challenges in Africa’s most populous country, struggling to contain Islamist insurgencies in the north-east and communal violence over grazing rights in central states.
“There eres reports of organised and simultaneous attacks in villages in Danmusa, Dutsenma and Safana by armed bandits,” the statement said.
“Detachments of police, Nigerian Army, Nigeria Air Force, Civil Defence and Department of State Services were drafted to the area,” it added.
President Muhammadu Buhari, in a statement, said he would not tolerate killing of innocent people by criminal gangs.
“In line with my commitment to security of the people, these attacks will be met with decisive force,” said Buhari, who is from Katsina.