Violence in north-west Nigeria has forced around 20,000 refugees to seek safety in neighbouring Niger since April, the United Nations refugee agency said.
Military, police and state security forces are deployed in northwest Nigeria to tackle criminal gangs behind a spate of killings and kidnappings.
Security forces are stretched tackling the decade-long insurgency by Islamist group Boko Haram in the north-east.
“This is not Boko Haram related in any way,” UNHCR spokesman Babar Baloch told a media briefing. “People are reportedly fleeing for multiple reasons, including clashes between farmers and herders of different ethnic groups, vigilantism, as well as kidnappings for ransom,” he said.
He said people were fleeing to Niger, to the north, due to the surge in crime in the Nigerian states Sokoto and Zamfara.
Zamfara is worst hit by the upturn of violence that killed dozens since the start of the year. The surge began last year and prompted deployment of the air force and 1,000 security personnel to the state.
Nigerian authorities in April suspended mining in Zamfara amid concerns illegal miners were connected to a rise in banditry.