Giving the sequence of events, Singh said the Mi-17 helicopter was fired upon at around 1700 hours from hills surrounding the area causing injuries to the police wireless operator, who was one of the seven occupants of the chopper.
The helicopter had to land under emergency conditions at an undesignated place, 2.25 km from Chintagufa police station.
But the six IAF personnel, including two commandos of elite Garud force, abandoned the injured wireless operator and also their weapons and the helicopter, he said.
On being informed, CRPF's anti-Naxal 'CoBRA' unit jawans marched towards the area where incident took place and located the chopper at around 2200 hours.
The injured wireless operator was evacuated to Chitagufa police station next morning.
The home secretary said the landing site of the helicopter at Timlewada was not properly sanitised by the Chhattisgarh police and the home ministry was taking up the issue.
"...I request you to kindly have the matter inquired into and take action as deemed fit," Singh said in his letter to the defence secretary.