Warning: This post contains graphic and upsetting videos.
Gaunt sun bears in an Indonesia zoo, so hungry they've taken to begging visitors for food and eating their own faeces, have been captured on video by animal rights activists.
Footage shot by the Scorpion Wildlife Trade Monitoring Group showed several emaciated bears at a zoo in the Indonesian city of Bandung.
While bears in enclosures very rarely beg for food, you can see the bears rushing for pieces of fruit thrown in, and begging visitors for more.
Another video also showed a bear eating its own feces.
"The bears are kept in a concrete cage and no grass. [There is] nothing natural, it is all very cruel", Marison Guciano, senior investigator of the Scorpion Foundation told Mashable.
The group has been sending investigators down to the zoo from mid-last year to monitor the bears' habitat.
Guciano added: "[It is] one of the worst zoos in all of Indonesia. Maybe it would be best if this place was closed down now, before more animals die a painful and avoidable death."
The Bandung zoo was also implicated in an alleged case of neglect last year, when its endangered Sumatran elephant died after it fell ill.
After the bears' videos went viral, a petition looking to shut the zoo down was started, and has reached over 200,000 signatures.
A sun bear at Sydney's Taronga zoo
Visitors have left numerous critical comments on the zoo's TripAdvisor page, with many accusing the zoo of neglect.
"I could not believe how disgusting and unclean this place was," said a commenter. "The animals are poorly maintained, underfed and generally ignored."
"Rusty cages, dirty place and really neglected animals. Some of them are very thin. Hell on earth for all these poor animals", said another review.
Sun bears as typically found in forest habitats in Southeast Asia and have been classified as vulnerable by the International Union for Conservation of Nature.
The Bandung zoo is not the first in Indonesia to be called out for its poor conditions, with another zoo in the city of Surabaya having been dubbed the "Zoo of Death".