A 13-year-old boy is fighting for his life after being hit by a car as he walked along the pavement.
The driver and passenger of a Jaguar failed to stop following the crash in Wigan at about 16:30 BST on Tuesday, police said.
The boy is thought to have been walking along Old Road in Ashton-in-Makerfield when the car hit him and then a wall.
A 15-year-old boy has been arrested on suspicion of causing serious injury by dangerous driving.
He remains in custody for questioning, Greater Manchester Police said.
The 13-year-old sustained serious injuries and was taken to hospital where he remains in a life-threatening condition.
Old Road was closed for around six hours while police investigated but has since reopened.
Sgt Darren Hancock appealed for witnesses and dash-cam footage.
He said: “We are very much keeping an open mind and would make a direct plea to anyone who may have been involved, or has the slightest bit of information, to do the moral thing and come forward.”