Injuries to a man in Marsham Street SW1 have been confirmed as neither life threatening nor life changing.
Police were called at 13:06hrs on Thursday, 15 August to Marsham Street, outside the Home Office, to a report of a man with a knife at the location.
The Met’s specialist firearms officers attended within six minutes to find a man, aged in his 60s, suffering with knife injuries.
London Ambulance Service attended the address and took the victim to a central London hospital. The injured man's family has been notified.
The incident took place outside the building.
Officers quickly detained a 29-year-old man near the scene at Smith Square who was arrested on suspicion of grievous bodily harm and possession of CS spray.
He was taken to a central London police station where he remains in custody.
At this early stage of the investigation, the incident is not being treated as terrorism-related, although officers are still keeping an open mind with regards any possible motive.
Enquiries remain ongoing to establish the full circumstances of the incident.