Armed men killed four people, including two policemen, and kidnapped at least 40 others in an attack on Kaura Namoda, in Nigeria's northwest Zamfara state, police and residents said on Tuesday.

Africa's largest economy is grappling with a multifaceted security crisis, including kidnappings for ransom in the northwest, which has reached alarming proportions.

Zamfara police spokesperson Yazid Abubakar confirmed the attack and said reinforcements have been deployed to the Kasuwar Daji district of the town where the incident took place.

Residents, including some of the victims, told Reuters by phone about their ordeal which began with an attack on the local police station.

"Sporadic gunshots woke me up around 0100 GMT. They started with the uniformed men before they moved into our houses," Hussaini Mohammed said.

"They took more than 40 women and children, including some elderly men," added Mohammed, who managed to escape.

Hamisu Kasuwa Daji, who heads the town's transport union, told Reuters his son and two grandchildren were taken by the attackers.

"My house is adjacent to the police station. The bandits started attacking the police station, which they engaged for several minutes until they killed two policemen and two other civilians.

"Then they proceeded to my house, by which time I had already fled. After I returned home later, I realised they had taken my son and two grandsons," he said.

Gangs of heavily armed men referred to as bandits by locals have wreaked havoc across Nigeria's northwest in the past three years, kidnapping thousands of people, killing hundreds and making it unsafe to travel by road or to farm in some areas.

Widespread insecurity is exacerbating a cost-of-living crisis caused by the policies of President Bola Tinubu who has not yet said how he plans to tackle the mounting problems.

Reuters