Police said two people had been stabbed in an ongoing incident in central London on Friday, with armed officers on the scene at Sony Music UK's head office in Kensington.
London's Metropolitan Police said they were called to an incident at Derry Street at about 1100 GMT. They said one person had been arrested and it was not being treated as a terrorism incident.
"Officers, including firearms officers, and London Ambulance Service are in attendance," police said. "Evacuations are in place as precaution. Two people have suffered stab injuries we await an update on their condition."