Scotland Yard said police were called at 5.30pm to Harcourt Road, Plaistow, where the boy was discovered with a gun shot injury. But his injuries were not deemed life threatening. Ten minutes later police were called to a car on fire on Chesterton Road, Plaistow.
Police believe the car is the same vehicle involved in the shooting.
Both the crime scenes are still in place.
There have been no arrests.
This is a breaking news story. More to follow.