At least 12 people were killed and three others abducted when gunmen attacked a mining site in Atoso village in Nigeria's restive Plateau state, a local group leader said on Wednesday.

Dalyop Solomon Mwantiri, who heads the Berom Youth Moulders-Association (BYM) said the attackers, struck late on Tuesday, leaving five others hospitalised with gunshot wounds.

Police spokesperson Alfred Alabo confirmed investigations were underway.

Tuesday's attack came just days after four children were killed in a nearby village, Mwantiri said. The BYM is urging the government to deploy more security forces to enforce a ban on open grazing, and rescue the abducted victims.