The woman was one of six people in a car involved in a collision on Baildon Road, in Bradford, after the vehicle failed to stop for officers on Tuesday night, the Independent Office for Police Conduct (IOPC) said.

The watchdog said it had begun an investigation after a referral from West Yorkshire Police.

The watchdog said in a statement: "We received a mandatory referral from West Yorkshire Police following the incident on Baildon Road advising that a silver Vauxhall Vectra had failed to stop for officers, and a pursuit was subsequently authorised, shortly before the collision at around 11.50pm."

It added that the 18-year-old woman, who was a passenger in the car, was pronounced dead at the scene.

Three men and a woman were taken to hospital for treatment and another man was arrested and received medical attention while in custody, it said.

IOPC regional director Thea Walton said: "I would like to offer our condolences to the family and loved ones of the young woman who died in this tragic incident. Our thoughts are with all those affected.

"It is important that we understand the events leading up to the collision. Our independent investigation will be thorough and look at the actions and decision-making of police.

"As our work is at an early stage and it would not be appropriate to comment further at this time."

West Yorkshire Police said a 21-year-old man was arrested on suspicion of causing death by dangerous driving and a 26-year-old man was also detained in connection with the incident.

Both remain in custody.