A bloody riot in a prison in South has left three people killed and 26 others injured.

Inmates clashed with guards at St. Albans prison outside Port Elizabeth on Monday, with no immediate reports available as to whether the fatalities were prisoners or guards.

“There was a clash between prison officials and inmates resulting in the deaths of three people and 26 others injured,” Correctional Services spokesman Logan Maistry said, adding, “We cannot say how many are prisoners and how many are officials. We are concerned at seeing that the injured receive medical attention and that the situation returns to normal.”

Police and emergency teams rushed to the scene as guards in St. Albans were struggling to impose order at the facility. Later reports said 10 of those injured were in critical conditions.

Officials said an investigation had been launched into the deadly quarrel and that senior officials, including South Africa’s Justice Minister Michael Masutha, were planning to visit the prison on Tuesday. A lockdown was enforced and officials turned away visitors who had arrived to see relatives.

The prison in East Cape Province has a history of bloody riots involving attacks by inmates on prison wardens. The facility saw a major riot in 2013.

Maistry said caution had been taken over the holiday period as special security measures had been put in place to tackle any protests or unrest in prisons during that time.

South Africa’s main opposition party, the Democratic Alliance, called for full inquiry while criticizing the government for allowing the riots to happen in prison facilities.

“It is not the first time that violent events have occurred at this prison and we cannot allow such incidents to go unaccounted for,” said the party in a statement on Monday.