A kangaroo in a zoo in southeast China died, while another was severely injured after visitors pelted rocks at them to make them hop.

The 12-year-old female kangaroo died in a zoo in Fuzhou, the capital of the Fujian Province, in March, but the news was made public this week after local newspaper The Haixia Metropolis News, published a report after speaking to a few zookeepers.

The visitors reportedly threw the stones on February 28, and the kangaroo died days later. An autopsy showed the cause of death to be a ruptured kidney, AFP reported.

“Some of us saw visitors throwing stones, and an attendant went to stop them but the visitors denied doing it,” a Shanghai news website, The Paper, quoted an unidentified veterinarian at the zoo as saying.

It is not yet clear if any of the visitors were punished for the act. Zoo authorities, however, said they plan to install security cameras to stop visitors from harming animals, AFP reported.

Several Chinese zoos have been in the news for the dismal conditions in which animals are kept. In larger cities, however, zoos have been working on improving conditions as they are faced with criticism from citizens and animal rights activists, The New York Times reported.

In 2003, there was widespread anger after a university student in Beijing threw sulfuric acid on bears in the city’s zoo. In 2016, animal rights activists demanded that a shopping centre in southern China free a polar bear that had been confined in a small display case at the mall.