Two children have been killed and their mother seriously injured in a crash just moments after a witness claimed they saw two other cars “racing”.

The boys, aged 23 months and 10 years old, were travelling in a BMW car with their mother, when the collision happened.

The crash, involving three cars, happened on the Birmingham New Road at the junction with Lawnswood Avenue in Wolverhampton at 8.45pm on Thursday, West Midlands Police said.

A witness said their son spotted two vehicles “racing” towards the junction, before the BMW was struck with an “almighty bang”.

Crash sceneThe scene of the crash. (Matthew Cooper/PA)

The 31-year-old driver of a Bentley car was arrested on suspicion of causing death by dangerous driving.

The driver of an Audi S3 car left the scene, police added.

Investigators have urged people, who recalled seeing a white Bentley Continental convertible and a blue Audi S3 travelling along Birmingham New Road around the time, to get in touch.

Police have also appealed directly to the Audi driver to “make contact”.

The force has confirmed that the speed of the vehicles involved is one line of enquiry.

More details have emerged of what one resident living near the scene described as a “massive” crash on what is the main arterial road between Wolverhampton and Birmingham.

In the immediate aftermath, several members of the public rushed to help and carried out CPR in the road, in a bid to save the injured children, while a woman was heard “screaming”.

One man, whose flat overlooks the dual carriageway leading to the accident scene, said the BMW was hit shortly after his son spotted two cars apparently racing towards the junction.

The resident, who asked not to be named, said: “I didn’t see it but I heard it – two cars must have been racing.

“My son ran to the window and said ‘they are racing dad’ and then we heard an almighty bang.

“My missus ran down to see if she could help and all the police and ambulance workers were there.

“You could see the police officers stopping the traffic were really, really distressed.”

JunctionThe accident happened at the junction of Birmingham New Road and Lawnswood Avenue, Wolverhampton. (Matthew Cooper/PA)

A local care worker, who also asked not to be named, said several crashes had occurred at the junction in the past 18 months because of motorists passing the lights on red.

Another man, who saw the aftermath, heard a woman “screaming”.

He said: “I didn’t see the accident itself but I think it was at about 8.40pm.

“There were a few cars involved and one car had been pushed through the railings.”

Describing the wrecked white BMW, he said: “There were car seats in the back. It was completely written off with the airbags deployed.

“There was a man lying in the road and he looked injured, and I heard a woman screaming about 10 minutes after it had happened.

He added: “It’s very sad to hear that children have been killed.”

West Midlands Ambulance Service said when its crews arrived, the public were already trying to aid the injured.

A spokesman said: “There were three patients who all came from the same car.

“Unfortunately, it soon became apparent that nothing could be done to save the two young boys who had been badly hurt and they were confirmed dead at the scene.

“A woman who had been driving the car was assessed and treated at the scene by ambulance staff before being taken to the major trauma centre at Queen Elizabeth Hospital Birmingham.

“Her injuries are not life threatening.”

Detective Sergeant Paul Hughes, from the police’s serious collision investigation unit, said: “This is an extremely tragic set of circumstances which has left a family totally devastated.”

He added: “I would appeal directly to the driver of the Audi to make contact with us.

“You may not be fully aware of the full tragic circumstances but you now need to speak to us.

“I would also ask the public who have any information or recall seeing a blue Audi S3 and a white Bentley Continental convertible travelling along the Birmingham New Road to make contact.”

He said: “The investigation is in its early stages and I would also ask the public to think about the family at this tragic time and not to speculate on the circumstances surrounding the collision.”