NEW DELHI, March 13 (Xinhua) -- The death toll in the forest fire in the southern Indian state of Tamil Nadu has risen to 10, with the recovery of one more body, police said Tuesday.

The fire broke out late Sunday evening when a group of nearly 40 people, mostly young college students, went trekking in Kurangini hills in Theni district, 540 kms from state capital Chennai.

"The death toll now stands at 10 while 30 have been rescued. The injured are being treated at a local government hospital where a few of them are said to be critical," a police official said.

Indian Prime Minister Narendra Modi has lauded the Indian Air Force which pressed into service its commandoes and choppers to rescue 30 trekkers as well as douse the flames, and condoled the deaths in the forest fire.

"I would like to appreciate RM @nsitharaman Ji, the Indian Air Force, the Garud Commandos and the local administration for their stupendous efforts during the rescue and relief operations in the wake of the Theni forest fire," Modi tweeted.

"My condolences to the families of those who lost their lives in the Theni forest fire. I hope that those who are injured recover soon," he added.

A probe has been ordered to ascertain the cause of the fire, the official said.

Forest fires are uncommon in India.