London's Air Ambulance was scrambled after an 18-year-old man was stabbed in Dagenham.
Police received reports of an incident in Highgrove Road at 10.18am on October 18.
London's Air Ambulance was dispatched along with crews from the London Ambulance Service.
A Met Police spokesperson said: "Officers were called at 10:18hrs on Wednesday 18 October to reports of a stabbing in Highgrove Road.
"The Air Ambulance and the London Ambulance Service attended and the victim, a man of 18, was taken to hospital. His injuries were non-life threatening.
"A man has been arrested in connection with the incident and enquiries are ongoing."
Concerned Facebook users described seeing "police everywhere and a rapid response car".
The London Ambulance Service has been contacted for comment.
