A two-year-old girl and a 12-year-old girl are seriously injured in hospital following a hit-and-run crash.
Police are appealing for information following the collision, which happened when a blue Volkswagen Golf lost control in Harwood Street in Blackburn, Lancashire, hitting a red Volkswagen Golf travelling in the opposite direction.
Officers said the occupants of the blue car got out of the vehicle. A white Vauxhall Astra van arrived at the scene a short time later.
One of the occupants then got into the boot of the van before it drove off towards Eanam, police said.
The two girls, both passengers in the red Golf, are being treated at Royal Manchester Children's Hospital.
The 12-year-old suffered a fractured skull and internal injuries, while the two-year-old suffered head and neck injuries.
The driver of the red Golf, a 39-year-old woman, suffered minor leg injuries in the crash, which happened at about 3pm on Friday.
Sergeant Adam Dawson, from Lancashire Police, said: "This collision has left two children with serious injuries and an investigation is under way to trace the occupants of the blue Volkswagen Golf and the van.
"If anyone witnessed the collision or has any information that could assist with our inquiries I would urge them to get in touch.
"I would also appeal to the occupants of the other two vehicles involved in the collision to make contact with us."