The man, a front seat passenger in the car, suffered serious head injuries when the house brick smashed a side window and hit him.

Bolton police said the brick was thrown from a group of eight to 10 Asian youths as the Toyota Corolla was being driven along Lanchester Drive towards Quebec Street in Deane at 8.30pm last night.

The driver, who was not hurt, stopped the car and called for an ambulance on his mobile phone.

The passenger, who has not been identified, is an Asian man from the Deane area.

He was taken to Hope Hospital in Salford but, because of the extent of his injuries, was transferred to a specialist unit at the Royal Preston Hospital.

A spokesman at the hospital described his conditon this morning as "critical".

Today, as a hunt for the thrower of the brick continued, a detective condemned the attack and called on those responsible to search their conscience and come forward to help police.

Det Sgt Keith Isherwood said: "The area around Quebec Street is a busy part of Bolton and I am sure there are a number of witnesses to this incident.

"I urgently need to speak to anyone who saw the brick being thrown at the car, or anyone who saw the youths as they ran away.

"The victim has suffered serious injuries and is critically ill in hospital.

"I would urge anyone who can identify the yosuths to search their conscience and tell us who they are."

The attack is being treated as deliberate and detectives are investigating the possibility that an incident earlier in the day may have provoked the attack.

A spokesman for Greater Manchester Ambulance Servce said: "We were called at around 9pm to deal with an accident involving a Toyota after a brick was thrown at it.

"A man was taken to the Royal Bolton casualty department. The hospital had been put on standby as he was quite poorly."

Forensic experts will carry out an examination of the brick, which was still inside the car when police arrived.

Scenes of crimes officers were examining the vehicle this afternoon.

Police are also carrying out door-to-door inquiries in the area in the hunt for the youth responsible.

One local resident said: "The place was crawling with police last night so we knew that something bad had happened.

"I can't believe something like this has happened. It's so frightening."

Residents in the terraced homes along the 100-yard stretch of road, who are mainly Asian, expressed their shock this morning

One who asked not to be named said: "When I saw the roads had been blocked off I knew it was serious.

"There are a lot of kids on this street and I can't believe something like this has happened."

Anyone who saw the incident or who has information is asked to contact Bolton CID on 0161 856 5740, or Crimestoppers on freephone 0800 555 111. All calls will be treated in confidence.