The A26 has been closed overnight in Newhaven due to a serious collision which led to four people being taken to hospital.
A statement from Sussex Police said: "At About 7.38pm on Monday 27 May, a two-car collision occurred on the A26 at Beddingham.
"A blue Hyundai i30N, travelling south, collided with a green Mini Cooper travelling in the opposite direction.
"Two occupants of the Mini – a 43-year-old woman and a 14-year-old girl from Seaford – sustained serious injuries; and an eight-year-old boy sustained minor injuries. All three were taken to Royal Sussex County Hospital (RSCH) in Brighton for treatment.
"The Hyundai driver – a 23-year-old man from Peacehaven – was also taken to RSCH with minor injuries.
"Anyone who saw what happened, or who has dash cam footage of the incident, is asked to email firstname.lastname@example.org or call 101, quoting serial 1286 of 27/05.
According to Highways England, both lanes of the A26 were closed for several hours while the emergency services dealt with the accident.
West Sussex Fire and Rescue Service and the South East Coast Ambulance Service also were at the scene, Highways said.
The road appears to have been reopened, according to traffic reports.