Tourists in London were left amazed yesterday when they spotted a pod of dolphins swimming up the River Thames.
The Sun reports that three mammals were seen swimming to historic Tower Bridge – apparently in search of food.
Some surprised holidaymakers dialled 999.
The Met's Marine Policing Unit tweeted: 'Just received reports of 2-3 'Dolphins' passing Bermondsey Wall East heading up river towards Tower Bridge!'
They later added: "The dolphins appear to be taking in the London sights whilst they wait for the tide to turn & then will make a safe return to sea #clever"
Stephen Marsh, of British Divers Marine Life Rescue, told the The Sun: "They could have been chasing food, as the Thames is a lot cleaner nowadays.
"The route they took would be from the sea and they would have to return that way.
"The tide started dropping at 4pm so they may have started their journey back then."
In June 2001, a dolphin was pictured in the Thames near Blackfriars Bridge. Crowds watched as the animal played and at some points just lay in the water, appearing to enjoy the sunshine.
Dolphins show off cute and unusual talent
Dolphin masters the art of shooting hoops with his nose
Dolphin jumps out of sea to 'kiss' dog on boat