Rescuers worked into the night on Sunday to free a small whale stranded in the River Thames in southwest London, local media reported.
The team of rescuers arrived at the scene near a lock in Richmond at around 21:00 BST (2000 GMT) shortly after the whale, believed to be a minke, was first noticed on Sunday evening, media reports said.
A small crowd of people gathered to watch as the team worked to remove the whale from the lock, hosing the animal down, and then putting a large yellow float around it, video footage obtained by Reuters showed.
Nearly four hours later the whale was successfully moved to a safer location, the BBC reported.
The minke whale, a species commonly found in the North Atlantic Ocean, will be assessed by a vet to ensure it is healthy enough to be released, according to the BBC.