A teenager has been stabbed to death in west London.
Police were called to High Street in Uxbridge at about 16:40 GMT on Thursday.
The boy, who had been stabbed in the chest, was taken to hospital by ambulance but was pronounced dead less than an hour later.
Another teenage boy suffered a knife injury to his ear, but his injuries were not considered life-threatening, Scotland Yard said.
The force has granted itself enhanced stop-and-search powers, under section 60 of the Criminal Justice and Public Order Act.
This allows officers to search anyone in a designated area without “reasonable grounds”.