Two teenagers have been arrested after a police officer was attacked with a hammer in south-west London.
Scotland Yard said a uniformed officer was left with a cut and bruising to his head and was taken to hospital following the incident on Monday afternoon in Twickenham.
A 16-year-old and 18-year-old, both male, have been arrested on suspicion of GBH and taking a conveyance, police said.
Officers were called to an underpass by Jubilee Avenue, Whitton, at 3.30pm, following reports of two men on a moped behaving suspiciously.
The suspects attempted to make off after police arrived, but were prevented from leaving the area by the two attending officers.
Police said one of the youths on the moped produced a hammer and hit an officer over the head, injuring him.
Further police units were dispatched to arrest the two suspects, who fled the scene on the moped but were caught nearby.
A taser was used to help detain one of the suspects who was armed with a hammer, police said.
Scotland Yard said a knife and clothing, believed to have been discarded by the fleeing youths, was found nearby.
The teenagers were taken to a south London police station for questioning.
The injured officer is receiving treatment at a south London hospital, police said. No other injuries were reported.
Chief Superintendent Sally Benatar said: "These attending officers were brave and resilient in their efforts to stop these suspects.
"Even when presented with a dangerous weapon, they acted in the best traditions of the Met and stood their ground.
"Their determination led to these armed suspects being arrested. I am very proud of them.
"We all wish the injured officer a speedy recovery and appeal for anyone who saw the suspects behaving suspiciously around the underpass by Jubilee Avenue or High Street, Whitton area, to contact police."
Additional reporting by Press Association.
