Hunt for armed robber in ute in Adelaide

A man is on the run after ramming a car and threatening three teenagers with a gun in Adelaide's north.

Just after 11.30pm on Monday the gunman, who was driving a ute, chased and rammed the teens' car on Birch Avenue in Salisbury East.

He threatened the trio with the gun after smashing a window of their car and stealing their mobile phones and wallets.

Police say they believe the incident was linked to the teenagers throwing eggs at cars on Main North Road prior to the robbery.

The suspect is described as Caucasian and was wearing a red baseball cap, and grey top.