A bounty has been placed on the heads of two "heartless" Frenchmen who kicked a squirrel into the Grand Canyon.
Peta (People for the Ethical Treatment of Animals) are on the hunt for two men who lured the animal to the edge of the canyon in the US state of Arizona with breadcrumbs before kicking it off.
Another man can be seen photographing the sickening scene as the animal plunges to certain death.
The UK, US and French branches of animal rights group Peta have joined forces to offer a reward of £10,000 to find the pair "before they strike again".
A spokesman said people who abuse animals are a "danger to everyone".
"It is imperative that any community faced with a sadistic and violent act such as this take measures to find the culprit or culprits and bring them to justice," the spokesman added.
Grand Canyon National Park spokeswoman Kirby-Lynn Shedlowski said the exact place where the incident took place along the canyon was identifiable by the video's backdrop, but that their chances of finding the pair are "remote".
She added: "We realise that the video has been seen by a lot of people and that there's some sensitivity to treatment of wildlife."
Grand Canyon Chief Ranger Bill Wright said that if the men are found they face a charged of disturbing or harassing wildlife, which carries a maximum sentence of six months in jail or a $5,000 fine.
But he added it is unlikely the men could be prosecuted for animal cruelty as that would require the authorities to find the squirrel in the one-mile deep canyon and prove it had been killed or injured.
The original video clip, which was viewed 105,000 times but has since been removed from YouTube for violating its terms of service, was uploaded by tourist Jonathan Hildebrand, who filmed the pair kicking the squirrel into the abyss.
He said: "I was watching but I did not realise what was happening until it was too late. I do not know who they are.
"All I know is that they were French."