An armed gang killed at least 50 people in attacks on villages in the northern Nigerian state Kaduna, the state governor said during a visit to affected communities.
Governor Nasiru El-rufai said the gunmen are suspected to be come from neighbouring Katsina and Zamfara states and Niger, adding troops were sent to the area.
Hundreds have been killed in northwest Nigeria since last year, in attacks government attributes to bandits – a loose term for outlaw gangs carrying out robberies and kidnappings.
Houses and vehicles were set ablaze by gunmen in the Kaduna attack.
Police spokesman Muhammed Jalige said gunmen invaded the villages of Hashimawa, Marina, Kerawa, Unguwan Musa and Zariyawa early on Sunday.
Security experts say Nigeria can ill afford more instability as it struggles to contain Islamist insurgencies in the north-east, conflict in central states and militant groups in the Niger Delta to the south-east.
The death toll from violence continues to rise in Nigeria, along with incidents of kidnapping and robbery.
In a statement on Monday, President Muhammadu Buhari expressed regret over the killings and said government was “determined to frustrate and defeat” those responsible.