Emergency services are dealing with a serious accident which has closed the A1 northbound just south of Alnwick.
The crash happened about 6.20pm tonight near the Whittingham turn-off. A car had earlier been reported heading the wrong way down the A1 northbound carriageway.
Eyewitnesses who were caught in the queue reported several emergency vehicles in attendance, including at least three fire engines, two ambulances and three police cars. Fire crews appeared to be using cutting gear on one of the cars. Police officers put diversions in place, then cleared the backed-up traffic, telling motorists there had been 'a very serious accident'.
A message on Twitter from Northumbria Police at 6.45pm said: 'Officers are on scene of a collision on A1 northbound carriageway at Alnwick, diversions are in place at this time.'
Two minutes later, Highways England tweeted: 'A1 northbound between A697 and A1068 nr Alnwick is closed due to a collision.'
On Facebook, Diane Bronze posted: 'A1 stopped at Newton on the Moor, at least three ambulances - hope it's not as bad as I think.'
Another report from a driver heading south past the incident said it looked 'very bad'.
Update at 8.09pm: Road closure officially started at 6.39pm and is expected to continue until 8.59pm.
Update at 8.14pm: Road closure anticipated to end at 9.20pm.
Update at 8.27pm: A1 northbound closure now expected to continue until 11.40pm.
Update at 8.40pm: Road closure extended to 12.15am tomorrow.
Update at 9.39pm: A1 northbound south of Alnwick expected to be shut until at least 1.45am tomorrow.
Update at 10.07pm: Tweet from Highways England: 'All lanes are now open on #A1 northbound between #A697 and #A1068 nr #Alnwick, following an earlier collision.'