CHENNAI • Police in southern India have arrested two medical students after a video of one of them flinging a stray dog from the balcony of a two-storey building went viral, sparking outrage.

The footage shows one of the students beaming as he lifts the dog by the scruff of the neck to the ledge and finally tosses it over. The other student is thought to have filmed the incident.

An animal rights activist later found the dog injured but alive.

According to the police, the students said during questioning that they threw the dog and filmed it "just for fun".

Police in Tamil Nadu state arrested the pair, who are final-year students at a medical college in the state capital Chennai, and a local court granted them bail yesterday.

"The court has granted bail to the students. As per the bail order, they paid 10,000 rupees (S$200) each," said local police inspector Frank D. Ruben.

Police began searching for the students on Tuesday following a complaint filed by an activist from the government's Animal Welfare Board of India.

Activist Shravan Krishnan found the dog and posted a photo on Facebook on Tuesday of him holding the injured animal, which has now been checked by a team of veterinarians.

"Good news - The dog has been found alive. She is not able to walk properly. She is with us now. Will be under treatment. What breaks my heart is that she was still wagging her tail," he said.

Earlier, the Indian branch of the Humane Society International offered a reward of 100,000 rupees to anyone who could provide information leading to the students' arrest. Others called for stronger animal cruelty laws in the country.

"Med student smiles as he throws a terrified dog off a roof. Animal cruelty #law in India is a joke. #dogs#justice," Twitter user B. Jorgensen said.

In 2007, animal rights supporters created an uproar when municipal workers in the southern Indian high-tech city of Bangalore culled thousands of street dogs after a child was mauled to death by a pack of neighbourhood strays.

AGENCE FRANCE-PRESSE