A probe by the police watchdog into a collision in which two people died and three others were injured is underway.
Greater Manchester Police (GMP) said officers pursued a speeding car on Frederick Road, Salford, at around 11.40pm on Wednesday, and that the vehicle had collided with two other vehicles.
Two men from the pursued vehicle were pronounced dead a short time later.
A man and two women from one of the other vehicles were taken to hospital with serious injuries.
Independent Office for Police Conduct (IOPC) regional director Amanda Rowe said: "My thoughts are with the men's family and friends after this tragic incident.
"When someone dies following police contact, it is mandatory for forces to make a referral to the IOPC. Our role is to establish the circumstances of the incident and this work is already underway."
The incident - understood to have involved an unmarked police car - has been referred to GMP's Professional Standards Branch "in line with normal procedure", GMP said.
No arrests have been made.