A man was airlifted to hospital with a "major trauma" following a serious accident on the M65 this morning, say ambulance services.
The man, who is in his early 50s, suffered head injuries in the two-vehicle crash which happened at around 10.30am between junctions 6 and 7 of the eastbound carriageway.
Traffic came to a complete standstill on both sides of the motorway as cars were stopped to allow the air ambulance to land.
One vehicle is believed to have overturned during the incident but nobody is thought to have been trapped.
A spokesman for Highways England said: "The M65 in Lancashire is closed eastbound between J6 (Blackburn) and J7 (Church), due to an overturned vehicle. North West Motorway Police Group were in attendance.
"Road users wishing to continue their journeys eastbound are advised follow the "Hollow Circle" diversion symbol and leave the M65 at J6. At the M65 J6/A678 roundabout, take the third exit onto the A678 eastbound Blackburn Road. At the A678/A6185 junction, turn right onto the A6185 southbound and re-join the M65 at J7.
"The westbound carriageway was temporarily blocked whilst Air Ambulance attend the scene."
A spokesman for the police said: "M65 eastbound will remain closed for Police investigation work for a few hours yet. The motorway will need a full sweep as nuts and bolts are in the carriageway. "