Emergency services are at the scene of a three-car smash on the A5 in Northamptonshire on Tuesday night (November 2).
An eight-mile stretch of the road is likely to remain shut both ways between Weedon Bec and Kilsby for some time following the smash near Watford.
A spokesman for Northamptonshire Fire & Rescue said: "Full closures on both the A5 and the B5385 Station Road are expected to remain into tonight while the emergency services deal with the incident.
"Please avoid the area and use alternative routes to avoid delays."
East Midlands Ambulance Service paramedics are also at the scene.
National Highways says a diversion route using the A45, M1 and A428 is signed by a hollow black square.