Firefighters were called to Woburn Place in Bloomsbury this morning after a double-decker tourist bus collided with the overhanging branch of a tree.
The impact removed the roof of the bus. Four people were taken to hospital by London Ambulance Service (LAS). Around 40 other uninjured passengers were looked after by police and LAS staff in a nearby building.
The Brigade was called at 1312 and the incident was over at around 1420. Crews will remain at the scene to make the roof safe.
Two fire engines and a fire rescue unit from Euston and Islington fire stations attended the incident along with around 15 firefighters.