The attack late Monday in Wase district in Plateau state was the latest violence in an area that has long been a flashpoint for disputes over resources and outbreaks of intercommunal clashes.
Armed men invaded Zurak community, shooting sporadically and torching houses, Plateau’s state commissioner for information, Musa Ibrahim Ashoms, told AFP by telephone.
"As we speak, about 40 people have been confirmed dead. Zurak is a popular mining community," he said.
Local youth leader Shafi'i Sambo said at least 42 people had been killed in the raid.
Wase has deposits of zinc and lead, while Plateau as a whole is known for its tin mining industry.
Sitting on the dividing line between Nigeria's mostly Muslim north and predominantly Christian south, Plateau often sees outbreaks of violence sparked by disputes between nomadic herders and pastoral farmers.
Climate change has escalated tensions over grazing land, water access and other resources, such as the state's metal reserves.
Parts of northwest and north-central Nigeria have also been terrorized by heavily armed criminal gangs, who raid villages to loot and carry out mass kidnappings for ransom.
In January, intercommunal clashes erupted in Plateau's Mangu town that left churches and mosques burned, more than 50 people dead and thousands displaced.