The deaths of a Northern Irish soldier and two other UK troops at the hands of a rogue Afghan soldier was "shocking and surprising", their commanding officer has told an inquest.
Co Armagh man Lieutenant Neal Turkington, Major James Joshua Bowman and Corporal Arjun Purja Pun, all of 1st Battalion The Royal Gurkha Rifles, were killed in the attack on their base in Helmand Province on July 13 last year.
The inquest heard that Sgt Talib Hussein (23) shot Maj Bowman (34) from Salisbury, Wiltshire, dead in his sleeping quarters in Patrol Base 3 in Nahr-e Saraj district, near Helmand's capital Lashkar Gah.
He then fired a rocket-propelled grenade into the base's command centre, killing Lt Turkington (26) from Craigavon, and Cpl Pun (33) from Nepal, and wounding four other UK soldiers.
Lt Col Gerald Strickland, commanding officer of the 1st Battalion The Royal Gurkha Rifles, told the hearing in Trowbridge, Wiltshire, of the Afghan National Army's (ANA) reaction to the killings.
"They were horrified. They were shocked," the officer said.
"They were as surprised as we were and wanted to do anything to resolve the issue.
"The stand-in Afghan commander wanted to take 20 men and go after Talib Hussein but I didn't want to do that."
Col Strickland said no motive had been established for the attack and said the only report he had seen was on the BBC after the killings, when a man called Hussein contacted the corporation's bureau in Kabul to claim responsibility saying he had been angered by British conduct.
"What I saw was on the BBC from an extract of his telephone conversation and it was reported he was incensed because he had witnessed ISAF shooting a civilian, which I can categorically say hadn't happened," Col Strickland said.
The patrol base was split between communal areas and living quarters separate to the British forces and Afghan National Army.
Hussein had waited until the early hours of July 13 to attack.
There was no evidence to suggest that Hussein, who had joined the Army eight or nine months earlier, was a member of the Taliban who had infiltrated the ANA.
The inquest also heard that there was no evidence that Hussein had been taking drugs, although it was accepted that other members of the Afghan security forces did.
Col Strickland accepted there was a risk to his men from a rogue Afghan soldier but said it was not regarded as a "high one".
The inquest was adjourned until today.