"The sick and old Royal Bengal tigers who have lost their might for hunting would be rescued and rehabilitated in the home to be set up on an isolated island of the Sundarbans," said Atanu Kumar Raha, in charge of forest conservation in West Bengal.

"We will trap the tigers straying into the villages for hunting and send them to the rescue centre," he said, adding that the facility -- to be built over 45 hectares on Jharkhali island -- would be up and running in a year.

The Sundarbans, a world heritage site, is the largest habitat for the endangered tawny Royal Bengal tigers.

Wildlife experts say the species is on the brink of extinction because of poachers who sell tiger body parts for use in traditional medicines in Asia.

A tiger census last year found there were 274 Royal Bengal tigers in the Indian part of the mangrove forests, which stretches over an area of about 3,500 square kilometers (1,350 square miles), Raha said.

The Sundarbans also extend into Bangladesh.

Between 3,500 and 3,700 Indian tigers are left in the wild in India, according to official government estimates that are increasingly in dispute -- down from about 40,000 tigers before India's 1947 independence from Britain.

Raha said the Royal Bengal tiger was a very efficient hunter, but old age robbed the animal of its ability to catch prey.

"In old age, they develop a tendency to stray into the island villages by night to hunt cattle and return to the forest by swimming hundreds of kilometers with their prey," he said.

Tigers kill nearly 50 people every year who enter the Sundarbans to collect honey or fish in the creeks and rivers, Raha said.

He said there had been 14 cases of tigers straying into the villages in the past year in the Sundarbans.

In three cases, tigers were trapped and released into the forest.

Raha, however, said wildlife officials did not know the number of old and sick tigers.