Gunmen killed a dozen worshippers, including an imam, and kidnapped several others from a mosque on Saturday night, local residents said on Sunday, in the latest attack by armed gangs in the north of the country.

Armed gangs, known as bandits, attack communities where security is stretched, killing people or kidnapping them for ransom. The gangs also demand villagers pay protection fees to be allowed to farm and harvest their crops.

Lawal Haruna, a resident of Funtua, in President Muhammadu Buhari's home state of Katsina, told Reuters by phone that the gunmen arrived at Maigamji mosque on motorbikes and started shooting sporadically, which forced worshippers to flee.

About 12, who were attending night prayers, were caught in the gunfire and killed, including the chief imam, said Haruna.

"They then gathered many people and took them to the bush. I'm praying that the bandits release the innocent people they abducted," said Abdullahi Mohammed, another resident of Funtua.

Katsina state police spokesman Gambo Isah confirmed the attack and said state-backed vigilantes, with the support of some residents, had managed to rescue some worshippers.

Katsina is among several states in the northwest of Nigeria which share a border with neighbouring Niger, allowing the gangs to move freely between the two countries.

Nigeria's military has been bombing bush camps used by the bandits, but the attacks continue, raising fears about the safety of voters who will go to the polls to choose Buhari's successor in February.

Reuters