Police have released a facefit of a man believed to be responsible for threatening and robbing a group of teenagers in Wanniassa last month.
The three teens were sitting on the Wanniassa Playing Fields on October 26 at about 4.30pm when they were approached by a man and boy riding a dirt bike.
Police say the man threatened the trio with a knife and forced them to hand over two ipods and a mobile phone.
He rode off with the boy down Wheeler Crescent towards Hyland Place.
The man is described as Caucasian, skinny, about 20 years old with short brown or blonde hair and a rat's tail. He was wearing a black T-shirt and tracksuit pants with a black bumbag.
The boy was Caucasian, between six and 10 years old with short blonde hair and a rat's tail. He was wearing a blue long-sleeved jumper and dark pants.
Police believe the pair were also responsible for an attempted aggravated robbery in Oxley on Sunday October 28 at about 10.20pm, where they demanded a phone from a teenager on Erindale Drive.
The teenager ran away before he was robbed.
Anyone with information is urged to contact Crimestoppers on 1800 333 000 or at www.act.crimestoppers.com.au.