The boys were on Springfield Road, Heath Town just after 3pm on Sunday(SEP20) when a car mounted the pavement and struck both of them, before hitting a parked car and driving off.
The 13-year-old, a friend of the younger boy’s brother, was on his bike and suffered cuts and bruises. He was treated at the scene by paramedics.
The four-year-old was flung in the air and was taken to hospital with a suspected broken leg. His mother also received minor injuries.
Detective Sergeant Louise Stafford, from West Midlands Police Force CID, said: “This was a shocking incident where two young boys were fortunate not to have suffered significantly more serious injuries. The driver of the car would have known that he had struck them and yet still left the scene with no thought for their welfare.
“We urgently need to trace the driver to bring them to justice, therefore we are appealing for anyone who knows who may be responsible to contact us.
“We believe the car was a Ford Fiesta and was a bright colour, maybe green or orange, and will now have collision damage.
“We are continuing to speak to witnesses and trawling CCTV of the area to trace the car.
“I would urge anyone who has information or dash cam footage to get in touch with us.”
Police can be contacted via Live Chat at west-midlands.police.uk between 8am and midnight, via 101 anytime or on Crimestoppers anonymously on 0800 555 111 quoting log 2775 of September 20.