According to eyewitnesses, there was a loud bang before the pilot bailed out.
Local people reached the crash site at around 3:00 pm and took the injured pilot to a school at Lik, Col Gurung said.
Since the area did not have roads two helicopters were sent from the Hashimara airbase to land at the school grounds to evacuate the injured pilot, but they could not do so, he said.
The pilot was then taken from the school on foot by rescuers comprising local people, police and army personnel to Passinggang on the North Sikkim Highway, he said.
The fire, which broke out in the wreckage of the aircraft, was controlled, Col Gurung said. "A court of inquiry has been ordered into the crash," IAF Group Captain Amit Mahajan told PTI in Shillong.