A man died after the car he was travelling in crashed into a lamppost following a police chase in Burnley.
Police say the vehicle was being following after it was requested to stop by an officer at around 1.25am this morning.
The car, containing three men, was travelling along Colne Road in Burnley close to the junction of Jackson Street.
The front seat passenger, a 23-year-old man from Burnley, died at the scene when the car crashed into a lamppost.
The driver and back seat passenger were taken to Royal Preston Hospital where they are being treated for their injuries.
A Lancashire Police spokesman said: "Prior to the collision, the vehicle had been requested to stop by the police and was being followed. As a result, the incident has been referred to the Independent Office for Police Conduct (IOPC) who are conducting an independent investigation."
Det Ch Supt Neil Ashton said: “Our thoughts are with the families of these men at this incredibly difficult time. We have specially trained officers supporting them.
“If you think you saw anything that could help with the investigation please call us on 101 quoting incident number 136 of September 29th.”
An IOPC spokesperson added: “We are investigating police involvement prior to a fatal road traffic collision in Burnley early this morning. We were notified of the incident by Lancashire Police and sent investigators to attend the scene this morning in Colne Road, Burnley and to police post-incident procedures.
"We have since declared an independent investigation. We understand the incident happened at around 1.25 am today (Saturday) after a vehicle had failed to stop for police.”