Several people have been injured, one seriously, in a four-vehicle crash in Cornwall, police have said.
Devon & Cornwall Police confirmed the A39 was shut in both directions between Carland Cross and Truro following the crash, just after 12:15 GMT on Sunday.
Police believe up to 10 people could be injured.
The road was an alternative route for many during a weekend closure of the A30 between Chiverton Cross and Boxheater junction.
Drivers have been urged to avoid the area.
Police officers, the fire service and ambulance service are in attendance, the force added.
Heavy traffic was reported on the A30 closure diversion route on Sunday afternoon, on the B3285 westbound to Goonhavern and the A3075 from Chiverton Cross towards Penhallow.