One of the cars involved was a police vehicle. The collision took place just after 3.30pm yesterday afternoon on King Edward VII Avenue in Windsor. The police are now appealing for witnesses.
Shortly after it occurred, a spokesperson for Thames Valley Police told drivers to take alternate routes.
They said: “King Edward VII Avenue in Windsor is currently closed in both directions due to a serious road traffic collision.
“It is likely to remain closed for some time.
“Please avoid the area and find alternative routes.”
The force is now appealing for witnesses.
Inspector Sarah Bartlett of the Joint Operations Roads Policing Unit said: “I am appealing to anybody who was driving on King Edward VII Avenue at around the time of yesterday’s collision to please check dash-cam footage and contact us on 101 or online if it has captured anything that can assist the investigation.
“I would also ask anybody who witnessed the collision, but has not yet spoken to police, to please get in touch with us, quoting reference number 43220019525.”