DJ McLaren/A two-year-old boy has died after a car that had broken down was hit by another vehicle.
The boy, from London, had been in a Toyota Auris that had stopped on the A1 near Peterborough, and was hit by a Volkswagen Touran at about 18:20 GMT on Saturday.
Five other people from London who were travelling in the Toyota were taken to Peterborough City Hospital with serious injuries, police added.
A 64-year-old man has been arrested on suspicion of causing death by dangerous driving and was released on bail until 20 March.
The collision took place on the northbound carriageway past the Stibbington junction.
DJ McLaren/