Four Inmates Remain On The Run In WA - Motorists Warned To Lock Doors And Windows

A sixth inmate has been taken into custody following a mass escape from a maximum security jail in Western Australia's Mid West.

Four men remain on the run after the group escaped during a disturbance at the Greenough Regional Prison, which houses men and women, near Geraldton on Tuesday afternoon.

Five were captured earlier, WA Police said on Wednesday.

Bradley Silvester, 35; Alan McDonald, 28; Brendan Bartley, 22, and 18-year-old Darryl Councillor, remain at large and their images have been released as police continue the search 400km north of Perth.

Residents and drivers are warned to lock their doors and windows.

It's believed some inmates climbed onto a roof and others scaled a perimeter fence just after 4pm when prison officers went to extinguish a cell fire and "lost control of part of the prison", Corrective Services Commissioner Tony Hassall told The West Australian.

"It started with a cell fire and then there were a couple of other fires lit in the prison," he said.

"They broke into some staff offices, got some equipment and used that to cause some damage. From the information I have, they got some equipment and scaled the perimeter fence.

"We'll do a full investigation into exactly what happened and what the causes were."

Police from Perth and various regional stations have been sent to the area to support local officers in the hunt for the remaining escapees.

"Police remind the public to be aware of their personal safety if travelling or living in the vicinity," a police statement said.