One person has been killed and another seriously injured in a four-vehicle accident which has closed a section of the A43 between Kettering and Northampton.
The collision near the Mawsley roundabout took place at 11.45am this morning and involved a lorry, two vans and a car.
Witnesses said the air ambulance had been called to take casualties to hospital.
Police have released very few details, but it is understood that one person has died and a second is very seriously injured.
A Northamptonshire Police spokesman said: "The A43 between Mawsley and the A14 is likely to remain closed until 4pm this afternoon following a very serious road traffic collision at 11.45am this morning.
"Officers are at the scene carrying out investigations into what happened during the collision which involved four vehicles.
"Motorists are being advised to avoid the area completely while this work is completed."
Motorists have advised to avoid the area until at least 4pm while the vehicles are recovered from the scene.
The road has been closed between the Mawsley roundabout and the A43 junction with the A14. The road could be closed for longer.
The A43 is ranked as one of the worst roads in the county, based on its accident record over the last three years.
However, the number of fatal and serious accidents on the road has fallen dramatically in the last two years.
Further updates on the accident throughout the day
Full report and pictures in Friday's Evening Telegraph
The Northamptonshire Evening Telegraph has been asked by police not to publish pictures of the collision at this stage.