This is the moment beachgoers flee in terror after mistaking a pod of beached whales for a shoreline mass shark attack.
The shocking footage was filmed at Prainha (Little Beach) in Arraial do Cabo, Brazil, on New Year's Eve.
Dozens of swimmers can be seen screaming after spotting dorsal fins and huge tails thrashing around in the shallow water, which turns a dark red as the sea creatures churn up the dark sand.
Another clip shows hundreds of people gathered on the sand watching on in horror as a group of men run into the ocean to pull what they believed are sharks into deeper water.
But experts have revealed that the panicked swimmers were almost certainly fleeing from a group of harmless whales.
Biologist Marcelo Tardelli told Brazilian media the species seen in the footage is probably the dwarf sperm whale. "If confirmed, it is the first time this whale has appeared in Arraial and it is considered a rare species, being an important record for science," a town hall spokesperson said.
Some believe the marine animals in the video could actually be hourglass dolphins due to their white markings.
When officials later inspected the beach they found no beached whales, which they say probably managed to swim back out to sea. They confirmed the animals were toothed whales.
Although some witnesses were seen trying to calm the whales, the country's Environment Foundation said people should avoid approaching or touching stranded animals.
"In these cases, the most advisable thing is to wait for the arrival of specialised teams to help the animal," it said. Authorities said there was a massive stranding of dolphins in the same location in 2012.
Fishermen accused of 'luring' shark onto beach
A group of fisherman who were initially hailed as heroes for rescuing a stranded shark were accused on Friday of deliberately 'luring' the predator onto a popular Perth beach.
In a video of the incident on Wednesday night, the struggling shark can be seen on the shore at Quinns Beach, in the city’s northern suburbs, before beachgoers work together to get it back into the water.
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