Officers are appealing for witnesses following a stabbing in Hackney.
Police were called to Chatsworth Road, E5 at approximately 2330hrs on Saturday 7 February to reports of a stabbing.
On arrival officers found an 18-year-old male having suffered stab wounds to his upper body.
The injured man was taken to an east London hospital where his condition is serious but not believed to be life threatening.
Officers at the scene were threatened by a large group of around 30 people. The group had covered their faces and threw bottles and other missiles at police.
No officers were injured during this incident.
One emergency response team officer pursued and apprehended a suspect in connection with this incident despite continuing threats from a volatile crowd.
An 18-year-old man was arrested on suspicion of being in possession of an offensive weapon and affray.
He has been taken into custody at an east London police station. Enquiries continue.
Anyone who witnessed or has information concerning this incident should call Hackney Police by dialling 101 or call Crimestoppers anonymously on 0800 555 111.