Thirteen endangered Asiatic lions that only live in a forest in western India have been caught and caged after three villagers were killed in recent months, a wildlife official said Monday.

The pride of lions has been rounded up from Gir sanctuary in Gujarat state after at least one of the animals last week dragged a teenager from his village while he was sleeping and killed him.

Gujarat's chief conservator of forests, J A Khan, said the lions were captured in recent days from an eastern part of the protected forest in a bid to find the "man-eaters" responsible.

Khan said it was unclear why or how many of the cats had ventured outside of the sanctuary, their last remaining natural habitat, to find prey, describing the attacks as rare.

"Lions that have preyed upon humans will be analysed in detail, while the rest will be slowly introduced back into the wild," Khan told AFP. 

"We will be doing a scat analysis which includes testing the animals' faeces for human tissues, chemical analysis of their blood and even genetic analysis," he said.

The cats, slightly smaller than their African cousins and with a fold of skin along their bellies, have been increasing in numbers in Gir, with 523 recorded in the latest census.

Conservationists have suggested some of the lions be relocated to a different sanctuary, to reduce human-animal conflict and avoid being wiped out by disease or natural disaster.

In the latest attack, the 14-year-old boy was dragged from his sleeping spot in a mango orchid in Ambardi village near the forest on May 20. His father was also injured while trying to scare the animal away.

A lion also killed a 50-year-old woman on April 10 in a nearby village as she slept in an open field. At least one of the predators dragged and killed a 60-year-old man as he slept in his hut in Ambardi village on March 19. 

The Asiatic lion was listed as endangered in 2008, up from critically endangered in 2000, after numbers improved in the forest.

But the International Union for Conservation of Nature has warned that as the lion survives in only one area it remained vulnerable to extinction from an epidemic or large forest fire.