Geetha Thomas owes her life to a text message. The 38-year-old tea plantation worker was able to scramble onto the roof of her home in southern India as a herd of elephants rampaged through her village thanks to an alert on her mobile phone.

The warning was part of an initiative by the environmental group Nature Conservation Foundation (NCF) aimed at reducing the number of deaths caused by elephants in the area by alerting communities to the animals' presence.

Dozens of people have been killed by elephants in Valparai, a tea-growing area surrounded by forest in the southern Indian state of Tamil Nadu, where around 70,000 people live mostly as workers on tea estates.

The area is a key corridor for elephants migrating from one section of forest to another, and the local population has little choice but to coexist with the large animals.

NCF came up with the SMS scheme after research found that 36 of the 41 deaths from elephant attacks in Valparai since 1994 could have been prevented if the victim had received a warning.

The group set up a network of local people to observe the elephants and provides regular updates on their whereabouts, sending out SMS messages when they had pinpointed an elephant's location.

"In a split second, up to 1,500 people, mostly tea pickers, are informed in English and Tamil," said NCF researcher Ganesh Raghunathan.

The NCF also set up red beacon lights that are activated with a missed call from a mobile number and can be seen from far away, reaching people without mobiles or in areas where connectivity is poor.

NCF figures show that average annual deaths from elephants in Valparai have fallen from three to one since the scheme was launched in 2012.

Mani Megalai, a tea picker on an estate on the edge of the forest, says the warning have made her feel "much safer" than she did before.

"Everyone keeps a cell phone here for safety. Before we didn't know where the elephants were," she told AFP.

"Now that we do, thanks to the SMS, we feel much safer."