In the US, the killing of a gorilla at the Cincinnati Zoo after a four-year-old boy tumbled into the ape's enclosure, has triggered outrage.
More than 2,000 people signed a petition on www.change.org to criticise the Cincinnati Police Department and the zoo for putting down the animal.
Authorities said the youngster is expected to recover after being picked up out of the moat and dragged by the gorilla for approximately 10 minutes.
Director Thane Maynard said the zoo's dangerous animal response team decided the boy was in "a life-threatening situation" and that they needed to put down the 17-year-old 400-pound-plus male gorilla named Harambe.
"They made a tough choice and they made the right choice because they saved that little boy's life," he said. "It could have been very bad."