A 16-year-old boy has been arrested on suspicion of attempted murder after a police officer was stabbed in the stomach.
The police constable was seriously injured in a car park after attending reports of anti-social behaviour near Bunsen House in Bow, east London on Sunday night.
A knife was recovered, and the teenage suspect has been taken to an east London police station for questioning, Scotland Yard said.
The officer was taken to hospital with what police described as "a serious stab injury to the abdomen", after the incident at around 11.30pm.
The force added that there is not believed to be any link to extremism or terrorism.