Police have cordoned off Bretton Way in Peterborough this evening, Wednesday August 22.
The road is closed between between the Bretton Way BP Garage and Tyesdale Roundabout and police say it is likely to remain closed for some time.
Eyewitnesses at the scene told the Peterborough Telegraph that there has been a serious collision between a car and a motorcycle.
The air ambulance has attended the scene.
Nobody from Cambridgeshire Police is available to talk to the Peterborough Telegraph at this time but the public is asked to avoid the area.
Stagecoach East tweeted: "Road closure due to serious incident at South Bretton currently causing severe delays on services #2 and #3. Please accept our apologies for this incident, which is beyond our control."