This is the terrifying moment a beluga whale bit divers inside its aquarium.

Holidaymakers were left in shock as the massive marine mammal attacked two underwater swimmers at Chengdu Haichang Polar Ocean Park in Sichuan, China.

Dramatic footage shows the sea creature swimming toward one diver and biting the legs of a female worker on August 14.

Moments later, it lunged at another worker holding a camera, successfully biting his flipper shoes.

Both divers managed to swim away, while the beluga dove deeper toward a companion nearby.

Spectators could be heard screaming in fear during the nerve-wracking encounter.

Last year, on April 5, a woman taking part in an underwater photoshoot with two beluga whales at the Stone Forest Ice and Snow World in Yunnan, China, was attacked by one of the whales.

The beluga grabbed the holidaymaker's head in its mouth, removing her wig. She managed to swim to the surface and escape unharmed.

Belugas are generally friendly and social, but in captivity they may bite humans for several reasons. Playful behaviour, mistaken identity, stress, overexcitement, territorial instincts, health issues, or past conditioning can all trigger nips.

The China Cetacean Alliance estimated that at least 1,085 whales were still living in captivity in China in 2020 alone, including 202 beluga whales.