NEW DELHI, April 3 (Xinhua) -- An Indian Air Force's transport helicopter crashed during landing after catching fire in the northern Indian state of Uttarakhand Tuesday, injuring four people on board, defense sources said.

"The Mi-17 helicopter, which was ferrying stuff for the Indian Army, caught fire after it collided with an iron girder while landing at a helipad near a temple in the mountains. Four people, including the pilot, on board sustained injuries," sources said.

The injured are being treated by military doctors, sources said, adding that an inquiry has been launched.

The Mi-17 is a Russian-made military transport helicopter that can transport 36 armed forces personnel or 4,500 kg of load.