A man was tonight being held on suspicion of attempted murder after a police officer was injured trying to stop a moped rider in Balls Pond Road.

Scotland Yard said the Pc was in uniform when it happened. He was taken to a north London hospital with knee injuries but has since been released.

He was hurt after spotting a moped riding erratically in Balls Pond Road at about 4.15pm. He signalled for the rider to pull over but was hit by the vehicle and knocked over.

The rider came off the moped and was detained by another officer.

Commuters reported traffic jams stretching between Dalston and Highbury Corner as the rush hour got under way and one person said there were “more police officers at the scene than they’d ever seen in one place”.

An 18-year-old man was arrested on suspicion of attempted murder, taking and driving away and possession of a Class B drug and remains in custody.

Officers also discovered the moped had been reported lost or stolen.

Det Sgt Jean-Pascal Barbe, of Islington Police, said: “This shows the dangers that officers face on a daily basis as they go about their work of keeping the people of London safe.”

Enquiries into the circumstances continue. Anyone with information is asked to call police on 101 or Crimsetoppers anonymously on 0800 555 111.