A video showing people cheering on an elephant swimming in a water-filled glass-sided tank at a Thai zoo has angered animal rights activists, who labelled the show animal abuse.

On Monday, World Animal News tweeted a video and said that an elephant in the Khao Kheow Open Zoo, southeast of Bangkok, was forced to perform a swimming show and had been hurt by a mahout.

The animal protection organization condemned the zoo and urged followers to give negative reviews on the website TripAdvisor.

Conditioning captive animals to perform requires physical exertion and breaks their spirit, according to People for the Ethical Treatment of Animals, a US-based animal rights group.

Zoo director Attaporn Sriheran said the show was exercise for the elephants as they play in the water tanks anyway, Khaosod English reported. He added there were other pools made specifically for the elephants to swim in. Visitors who watch can also learn more about animal behavior, he said.

Attaporn added that no elephants were hurt by mahouts. Instead, he said elephants and mahouts take care of each other like “bread and butter.” The zoo director also condemned the animal rights group for “tarnishing Thailand’s reputation.”

According to the zoo’s website, the elephant swimming show started in 2016 with two performances daily.