Emergency services attended a crash involving two cars in Chain Lane at around 11.40am on Friday (May 6).
Police closed the road in both directions between Bleasdale Avenue and Jubilee Gardens following the collision.
“The road is likely to remain closed for a number of hours,” a spokesman for Lancashire Police added.
“Please find an alternative route.”
North West Ambulance Service confirmed two land ambulances, an air ambulance and a rapid response vehicle attended.
Three casualties were extricated by fire service personnel before being taken to hospital, according to Lancashire Fire and Rescue Service.