Two men who died in a collision were being pursued by police for less than a minute beforehand, initial enquiries have found.
Patrick Connors, 36, known as Paddy, and Thomas Sharp, 29, known as Tommy, died after the Mercedes C-Class car they were travelling in crashed in Salford at about 11.40pm on Wednesday September 23, a spokesman for the Independent Office for Police Conduct (IOPC) said.
Initial enquiries by the IOPC showed officers in an unmarked Greater Manchester Police car used its emergency lights and siren to signal the Mercedes to stop, before a pursuit of less than one minute along Lower Broughton Street and Frederick Road.
The Mercedes collided with two VW Passat vehicles travelling in the opposite direction, the watchdog said.
IOPC regional director Amanda Rowe said: "The loss of these two men was a tragic incident and my thoughts are with their families and friends at this difficult time.
"When someone dies following contact with the police, it is mandatory for forces to refer the matter to the IOPC.
"We will be considering in-car footage, CCTV and witness statements to establish the circumstances of this incident and whether the local and national guidelines and procedures were followed.
"We will continue to keep the families of Mr Connors and Mr Sharp updated on our progress, as well as the force and the coroner."
The spokesman said the two women in one of the cars, a taxi, were taken to hospital with serious injuries which are not thought to be life-threatening.
The driver of that car suffered minor injuries and the other driver was uninjured.
Inquests into the deaths were opened on Thursday.