Police in Christchurch are investigating an ambush against a police sergeant late on Friday night.
They say he was set on by a gang of 300 youths in Wigram Road and an air rifle was fired at him.
Area commander Malcolm Johnston says the sergeant was responding to a call about boy racers spinning wheels and doing burn outs in the Wigram area.
Commander Johnston says the youths began throwing bottles and then a slug from the air rifle struck his car window, before the officer managed to make his escape.
He says the action was a virtual ambush of the officer by a gang of thugs, who were calling out for the officer to be killed.