New Delhi, Jan. 13: The manner in which NSG bomb squad head Lt Col E.K. Niranjan was killed in Pathankot while searching the bodies of the attackers is a mystery because the officer was trained for the job he was performing, army chief General Dalbir Singh Suhag admitted today.

"I must tell you the officer was trained. I have been told that in the last one year, he had handled 3,500-4,000kg of explosives," the general said.

General Singh said he had instructed the army commander to minimise casualties and not carry out combing operations at night. "Later on, I checked and I was told that all procedures were followed. But it is very difficult to say where things had gone wrong despite that. Maybe, it was a booby trap. But he (Niranjan) was most qualified to handle it. It is very difficult for us, you and me, from a distance to determine where things had gone wrong."

Witnesses had reported that many uniformed personnel were carrying mobile phones inside the air force station during combing operations.

Lt Col Niranjan was killed after a body of one of the attackers was tugged into the bay, as is the procedure, for examination when an explosive vest or grenade went off, killing him. He was not wearing a blast-shield.

All seven Indian soldiers killed in the operation have been declared "battle casualties". They included five from the Defence Security Corps - among them a veteran of the 7 Dogras, Jagdish Chand, who wrestled down a terrorist with bare hands before turning the attacker's gun on himself - an air force Garud commando and Lt Col Niranjan. This means the families will be entitled to the compensation the government grants for soldiers who have fallen in war.