Eight people have been hurt in a crash involving a commercial rigid inflatable boat on the River Thames.
Two men and two women were taken to hospital with what were believed to be minor injuries, London Ambulance Service said.
HM Coastguard was alerted at about 17:40 GMT following the boat's collision with a buoy, just off Greenwich Pier.
The Maritime and Coastguard Agency's enforcement team has been informed.
Just heard a loud bang on the Thames.... looked out to see a @thamesclippers possibly in distress w/most lights off & needing what looks like a fairly quick assist to the Greenwich pier. Now looks like joined by Police Boat of some kind. pic.twitter.com/LYw6HaVrCk— Thomas J. Quinlan (@thomas_quinlan) January 17, 2019
The Tower RNLI lifeboat was sent to help.
The Thames Clippers river bus service said one of its boats was assisting with the operation.
London Ambulance Service said it sent three ambulance crews, an incident response officer and a hazardous area response team.