A group of prisoners barricaded themselves inside a unit and set mattresses alight in a two-hour riot at Albany Regional Prison this afternoon.
More than a dozen police were called to the prison along with Department of Fire and Emergency Services crews after the disturbance was reported at 1.30pm.
Police assistance was requested by the prison along with heavy duty fire trucks which entered the prison confines.
The Department of Corrective Services say the disturbance involved four prisoners who set fire to a bin and four mattresses.
It is unsure what sparked the incident.
The Albany Advertiser understands flash grenades were used to diffuse the incident and the prisoners were returned to their cells by 3.30pm.
The spokesman confirmed damage is being assessed and no injuries were reported.
Police will investigate any offences arising from the incident.
WA Prison Officers’ Union secretary John Welch said the incident was extremely concerning and showed how dangerous being a prison officer could be.
"Albany is almost at twice its design capacity, it was short of staff, that makes it very difficult to manage," he said.
"We are working with the Department to try to manage the growth of the prisoner population but all of this chronic overcrowding dramatically increases the risk and danger for prison officers."
In April 2014, 20 prisoners barricaded themselves inside a unit for more than eight hours causing damage.
In March this year a guard was attacked by a prisoner with a metal pole with the WA Prison Officers Union claiming overcrowding was a contributing factor to violent incidents.
From the Albany Advertiser