A student of King Solomon High School in Barkingside is believed was stabbed while on his way into class on Wednesday morning.
There were reports that the boy, who was knifed at about 8.20am on Barkingside High Street, was taken to hospital by air ambulance. He is not believed to be Jewish, and his injuries are not thought to be life-threatening.
The Community Security Trust said it was working with the school, but that the “motivation remains unclear”.
An eyewitness told the Ilford Recorder: “There was a group of young boys and I think they were cycling. All I saw was a punch, I didn’t see the knife, and then a black boy fell down. Another black boy ran off.”
The school declined to comment. A spokesman from Redbridge Council said: “We are aware of this distressing incident, our best wishes are with the student and their family, but unfortunately we cannot comment on ongoing criminal matter.”