Pregnant woman punched in Melbourne road rage attack

A man has allegedly punched a pregnant woman in the stomach and attacked a policeman after a car accident in Melbourne.

Police say the man hit the 26-year-old woman in the face and abdomen and then punched the policeman after the crash in Broadmeadows on Tuesday night.

It's alleged the man's car crossed four lanes of traffic at a set of traffic lights and collided with the woman's oncoming car.

Police used capsicum spray to subdue him after the attack.

The pregnant woman and policeman are being treated in hospital.

The alleged attacker, who also suffered minor injuries, is being questioned.