Police are also investigating another two other assaults which took place in the same area on Saturday night.

At 12:40am it is believed the man was standing on a footpath at Campbell Parade, near Roscoe Street, when he was punched once in the back of the head by an unknown man.

The attacker then kicked the man while he was on the ground, before fleeing on foot.

The injured man was treated at the scene by paramedics before being taken to St Vincent's Hospital where was placed in an induced coma. He remains in a critical condition.

Police are looking for a man described as 183cm tall, with a strong build and wearing a denim jacket.

Two hours after the attack, police were called to Roscoe Street and Glenayr Avenue near Bondi Beach again at 2:45am after a man was hit on the head with a brick.

A man in his 20s received stitches at St Vincents Hospital after having a brick thrown at him by two men.

The alleged offenders robbed the bleeding man of his phone and wallet.

Police are continuing their inquiries. They have not spoken to the man and will do so when he is released from hospital.

Police are also investigating a six-man brawl which occurred just before 2am at Bondi Beach.

More to come.