A mining pit collapse in Galkogo village of Niger State in central Nigeria killed one person and left 30 others trapped, the state's emergency agency said on Tuesday.

Six miners were rescued with serious injuries, Hussaini Ibrahim, a spokesperson for the Niger State Emergency Management Agency (NSEMA) said in a statement.

The incident, at the underground gold mine, occurred on Monday after heavy rains softened the soil around the pit, triggering the collapse.

Rescue efforts are under way with excavators brought in, but difficult conditions and insecurity in the area are hampering operations, Ibrahim said.

Nigeria's Niger state is rich in minerals but plagued by insecurity.

Large-scale mining operations face violence from armed groups, while safety standards are poorly enforced at the large number of unregulated small-scale mines.