Police have arrested a man on suspicion of GBH following an incident at the junction of Russell Street and Museum Street around 10am on Tuesday 8 August.
A man was treated for a stab wound to the arm at the scene and taken by London Ambulance Service to hospital.
His condition is being assessed.
This was an isolated incident and there is no outstanding risk to the public. It is not being treated as terror-related.
The scene may be in place for much of today.
Anyone with information or footage which could assist the police investigation is asked to contact police on 101, quoting CADF 2184/08AUG, or anonymously via Crimestoppers on 0800 555 111.
