Car passenger stabbed at red lights outside Christchurch carwash

A car passenger is in a critical condition after being stabbed at a red light in Christchurch.

RNZ understands the driver objected to the loud music they were playing, in an apparent road rage attack, although police were yet to establish the circumstances.

Detective Sergeant James Haigh said the stabbing happened at the intersection of Clarence Street and Blenheim Road in Riccarton at 5.40pm Thursday.

"Two cars were at the red lights on Clarence Street, when a male has gotten out of one of the vehicles and attacked the victim who was in the other car."

The offender then fled, Haigh said.

The victim remained in Christchurch Hospital in a critical condition. Police confirmed he was the rear passenger in a red car carrying four adults.

The offending male was the driver and sole occupant of the other car.