Two men died and eight people were injured, one seriously, in a head-on collision involving two cars and a van.
It happened on the A20 Eglantine Lane in Farningham, near Dartford in Kent, at about 01:20 BST.
The two victims, aged in their 20s, died at the scene, South East Coast Ambulance Service said.
Police have appealed for anyone who saw a black Vauxhall Insignia with a 61 registration being driven on the A20 towards Swanley, to contact them.
A blue Citroen Berlingo van and a white VW Polo were also involved in the collision.
Sgt Glyn Walker, of Kent Police, said the two men who died were in the same vehicle.
He said there had been no arrests, but "one of those injured will be the subject of our enquiries".
The road was closed in both directions for more than 11 hours while an investigation was carried out.