Two men have died and three others injured in a crash during a police pursuit.
Officers began pursuing a speeding car in Frederick Road, Salford, at about 23:40 BST on Wednesday before it crashed with two other vehicles.
The men from the car died, and a man and two women from one of the other vehicles were seriously injured.
The Independent Office for Police Conduct (IOPC) has started an investigation into the crash.
Greater Manchester Police (GMP) said in line with procedure the crash had been referred to its professional standards branch.
No arrests have been made.
A spokeswoman for the IOPC said: "We have begun an independent investigation into a fatal road traffic collision in Salford last night which followed a police pursuit.
"We understand the pursuit involving an unmarked police car took place on Frederick Road, Salford at around 11.40 pm. The vehicle being pursued collided with two other public vehicles."
The spokeswoman added that "sadly two men from the pursued vehicle have since been pronounced dead".