A British army cadet was seriously injured tonight after picking up a device that exploded in his hand, Scotland Yard said.
The man, who has not been named, was taken to the Chelsea and Westminster Hospital in Chelsea following the explosion at the British territorial army base in White City, west London.
A Scotland Yard spokesman said: "We believe a male army cadet picked up an object and the object has exploded.
"The cadet was taken to Chelsea and Westminster Hospital with injuries to his hand and chest."
Explosives officers were at the scene and the area was cordoned off, although nobody within the cordon had yet been evacuated.
An anti-terrorist investigation team was probing the incident. The spokesman said there had been a thorough search of the area.
Police were called to the scene at 7.10pm by the fire brigade after reports of an explosion.
It was still unclear what had caused the explosion.
A spokesman for the British Ministry of Defence confirmed the blast happened at the base.