Part of the A11 is still closed after a crash involving two cars and a lorry near Mildenhall.
Police, fire and air ambulance services are still at the scene and a woman is believed to have suffered serious injuries.
The collision happened shortly after 11am.
The stretch of road between the Fiveways roundabout and the Elveden crossroads has been closed.
Diversions are in place, but drivers have been warned to expect major delays.
More top news
Any mist or fog should readily clear leaving a fine morning with some spells of warm sunshine.
A campaign has been launched to increase tourism revenue in Northamptonshire by 50% - masterminded by a former Saatchi & Saatchi director.
A change in wind direction brings warmer temperatures to the Anglia region