Motorists in Burnley are being advised to avoid the Colne Road area after a serious accident involving three cars.
It is believed a male driver collapsed at the wheel and struck two other vehicles. He was subsequently taken to hospital.
The two other drivers, one of which was trapped and had to be rescued by firefighters and paramedics, suffered minor injuries.
Colne Road is closed in both directions from Church Street to beyond Hebrew Road.
A police spokesman said the incident is on-going and drivers should expect the road to be closed for at least a few hours.