Less than a week after after reports that beloved hippo Gustavito was fatally beaten at an El Salvador zoo by nighttime mystery attackers, a crocodile was stoned to death by visitors at a Tunisia zoo.

Belvedere Zoo spectators hurled rocks at the crocodile’s head Tuesday, a zoo veterinarian said. Tunis city officials denounced the “savage behavior” and posted photos of the dead animal on Facebook showing a paving slab and large rock next to the crocodile’s bloodied head. The animal died of an internal hemorrhage.

“It’s terrible, you cannot imagine what animals endure from some visitors,” zoo veterinarian Amor Ennaifer told Agence France-Presse. Ennaifer said people often hurl rocks into the animals’ enclosures, frequently targeting lions and hippos. He said problems increase during school holidays.

“There are more than 150 species in the zoo. We can’t put a guard in front of each cage,” he said. “People need to be aware of the need to respect animals.”

The horrific attack follows reports of a brutal beating by attackers using metal bars, rocks, knives and an ice pick last Wednesday on Gustavito the hippo, a favorite attraction at San Salvador’s zoo.

Managers said they had no idea he had been attacked until they noticed he wasn’t eating the following day and lay huddled in his pool. Zookeepers said the 15-year-old hippo, whose body was reportedly riddled with wounds, died Sunday, despite 24-hour care. The zoo was conducting a necropsy to determine an exact cause of death.

However, new evidence suggests that the hippo may not have been attacked. El Salvador prosecutors have said that Gustavito died from pulmonary hemorrhaging ― bleeding inside the lungs. Officials have not totally ruled out an attack.

This article has been updated with new information on the hippo attack.