A rescue operation is under way in Liverpool after an amphibious tour bus with 30 passengers on board sank in the Albert Dock.
One of Liverpool's fleet of Yellow Duckmarine tour buses began sinking just before 4pm today in Salthouse Dock at the front of the Albert Dock complex.
A spokesman for the Maritime and Coastguard Agency said 30 passengers were on board.
It is understood that most of that number have now been accounted for, but a rescue operation involving police, fire, ambulance and coastguard crews is under way to find the remaining passengers.
The incident is the second sinking involving one of the vessels this year.
The last time it happened was in March and following that incident the buses' permission to go in to the water was suspended while an investigation was carried out.
A spokeswoman for the North West Ambulance Service said there had been no fatalities and that 31 people had been rescued.
One man was taken to hospital as a precaution and the incident was now being "scaled back," the spokeswoman said.
She added: "We are unaware that there is anybody unaccounted for but police are continuing to search the water just to see if there is anybody else affected and we are on stand-by."
Firefighters rescued three people from the water, a spokesman for Merseyside Fire and Rescue Service said.
Chief Fire Officer Dan Stephens said: "Three people have been rescued by firefighters from the water. We have had assistance from a number of agencies on scene. We are working with police, ambulance and coastguard to account for everyone on board.
"All firefighters on Merseyside are trained in still water rescue to allow them to safely enter canals and lakes and dock areas, such as in this incident, to help rescue anyone in need."
The three rescued by firefighters were adults.