A manhunt is under way for a man police say could be in possession of a firearm and other weapons.

Police need the public's help in locating Malcolm Blurton. Credit: WA Police

Police were urgently requesting the public's help to locate 30 year old Malcolm Stirling Blurton who they said was considered very dangerous and may behave in an unpredictable manner.

Blurton was described as dark skinned, approximately 175cms tall, with a medium build, short brown hair and possibly with a rats tail.

He was believed to be around the Armadale and Gosnells area and was last seen in a silver vehicle, possibly a hatchback or SUV.

If spotted members of the public were advised not to approach him but to call police immediately on 131 444.