Police are appealing for witnesses following a serious collision between a car and a flatbed van in Hooe, near Battle.
Officers were called to the B2095, near The Lamb pub, at about 3.05pm on Thursday (December 15).
Colleagues from both the fire and ambulance services also attended the scene to remove a seriously injured boy from one of the vehicles.
He has since been airlifted to hospital with potentially life-threatening injuries.
Anyone who may have witnessed the collision are being urged to come forward and any relevant information or dashcam footage is reported to Sussex Police by emailing collision.appeal@sussex.police.uk, quoting Operation Seville.
