The 16-year-old boy has was attacked on Billet Road in Walthamstow at around 3.45pm.
Police and paramedics raced to the scene and London’s Air Ambulance was also scrambled.
The boy was found with stab injuries to his neck and leg.
He was taken to hospital and his condition is unknown at this stage.
Police have imposed a Section 60 search authority on the area as their investigation into the attack gets underway.
Billet Road has been closed between North Countess Road to Durban Road while scenes of crime officers and forensics experts carry out detailed searches of the area.
Officers warned the road will remain closed for some time and have warned the public to avoid the area where possible.
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