WA prisoner still on roof after five hours

Authorities are still trying to talk down a man who has been sitting on the roof of a medium security prison in Western Australia for more than five hours.

The man managed to get on to the roof of Acacia Prison, northeast of Perth, early Tuesday forcing the facility into lockdown.

A Corrective Services spokeswoman said it was an isolated incident, not related to any riot, though it was unclear at this stage why he the man had done it or if he had any demands.

Trained staff were dealing with the matter, she said.