NEW DELHI (AFP) - A wild tiger has killed three people in southern India this month, forcing dozens of schools and a tourist resort in the area to shut down, an official said on Tuesday.

The tiger killed a woman working on a tea plantation in the state of Tamil Nadu last week, the animal's third victim since Jan 4, district forest officer Thiru Sugirtharaj Koil Pillai said.

The attacks come after searches got under way last week at the other end of the country for another tiger believed to have killed four people earlier this month.

After the latest incident, the Tamil Nadu government closed 45 schools in Nilgiris district and a resort on Doddabetta hill, a popular spot for holidaymakers, in case of further attacks, the official said.

Some 150 forest officials and police, aided by elephants and sniffer dogs, have stepped up a search for the tiger, setting up motion detection cameras and cages with meat to track and trap the animal.

"The tiger has been prowling around the tea garden, making it difficult to spot him. But hopefully, we will capture him by today or tomorrow," Pillai told AFP.

"It was only after the third killing, when a camera trap caught footage of the animal, that we knew for sure it was a tiger behind these deaths."

Conservationists blame towns and villages that are encroaching on tigers' natural habitats for the deadly incidents occasionally reported in India. But the official was at a loss to explain the latest attacks.

"There have always been tigers around this area, but they have never harmed humans before," said Pillai.

A wild tiger is believed to have killed four villagers in the northern state of Uttar Pradesh this month, prompting searches for the big cat and protests from villagers. The animal is thought to have strayed from a nearby tiger reserve.

India is home to some 1,700 tigers - half of the world's rapidly shrinking wild tiger population - but has been struggling to halt the big cat's decline in the face of poachers, international smuggling networks and loss of habitat.

The country has seen its tiger population plummet from an estimated 40,000 upon independence in 1947.