A man has been stabbed outside the entrance to BBC Radio 2.
Witnesses said two men were arguing on the street before one attacked another with a knife outside Wogan House in central London.
A 21-year-old man was later found by the Met Police and was taken to hospital for a stab injury on his hand.
BBC London's home affairs correspondent Nick Beake said there was some blood in and around the entrance to the building.
The Met Police said the injuries were not life-threatening and no arrests had been made.
It is not treating the incident as terrorism-related.
The entrance to the building has been closed.
Anyone with information should contact the police.