A police emergency response team quickly ended a disturbance on Saturday involving about 30 prisoners at the Fraser Regional Correction Centre in Maple Ridge, B.C.

The uprising started about 10 a.m. and ended four hours later with prisoners either being put back in their cells or arrested by police.

A spokesman for the Ridge Meadows RCMP says the disturbance was stopped without incident, and minor injuries caused to the prisoners were as a result of the disturbance, not from any confrontation with officers.

While there have been complaints of overcrowding at the facility, it's not known what set off the angry confrontation.

Both the RCMP and correctional centre officials will be investigating the cause of the disturbance.

Ambulance and fire crews were at the prison as a precaution, but the police spokesman said neither service was necessary.