Defence Force chief Air Chief Marshal Angus Houston said the patrol, with partners from the Afghan National Police, was deployed to the area, which is known to be an "insurgent distribution and supply cell". Sapper Rowan Robinson ... killed in Afghanistan Credit:Defence Department They discovered a large stash of weapons, including grenade launchers, ammunition, assault rifles and communication equipment, and the patrol was shot at. The patrol destroyed the cache and moved on to another area, where they again came under heavy fire from several directions, Air Chief Marshal Houston said. "During this second engagement, the special operations task group soldier was shot by insurgents while he was in an overwatch position," he said.

"His mates quickly moved to him under heavy fire, commenced first aid and called for an aeromedical evacuation. "Very sadly, despite these efforts, this young man could not be saved." The soldier's family have been notified. He was on his second tour of Afghanistan, having served in 2007 in a reconstruction taskforce. Air Chief Marshal Houston said the soldier was part of vital work in Afghanistan.

When you lose somebody there's always a sense of loss and sadness but there's also a steely resolve - this sacrifice will not be in vain Australia's Special Operations Task Group operates in Oruzgan, where most Australian troops are stationed, but also in the neighbouring provinces of Helmand and Kandahar, where the insurgent presence is stronger. "The discovery and destruction of this massive cache of weapons, ammunition and improvised explosive device components will undoubtedly prevent other casualties and will impede the insurgency in northern Helmand and in Oruzgan." Ms Gillard said she could not promise there would not be more hard days in Afghanistan. "As we enter the fighting season in Afghanistan we have to prepare ourselves for the possibility of more hard days to come.

"But I can promise you this: Afghanistan is not an endless war and it is not a war without a purpose. "We are crystal clear on our mission and we have a defiant time frame for our strategy. "We are making progess towards our goal of an Afghanistan that never again be a safe haven for terrorists." Air Chief Marshal Houston launched an impassioned defence of the Australian effort in Afghanistan, claiming that Australian troops are making a difference. He acknowledged for the first time that the public was turning against the war in Afghanistan.

But he said the recent spate of bad news was not indicative of the wider battle. "Our soldiers have a very high level of morale at the moment; they think they're winning, they think they're making a difference," he said. The last Afghan winter was significant in terms of success for western forces in Oruzgan province but, Air Chief Marshal Houston said, "we must expect more losses". "When you lose somebody there's always a sense of loss and sadness but there's also a steely resolve - this sacrifice will not be in vain," he said. The NSW-born soldier was a "superb young man" who was popular in his unit, Air Chief Marshal Houston said.

"He was also a great team member, dedicated and professional, whose range of skills and qualifications were more than you would rightly expect for someone so young. "Though nothing will ease their sense of loss, I want this soldier's family to know that their loved one, his SOTG mates and their Afghan National police partners were undertaking vital work in Afghanistan yesterday. In response to questions about waning public support for the war Air Chief Marshal Houston said the troops in Afghanistan had high morale, but acknowledged the Australian public were becoming increasingly sceptical. "I can understand the concern out there, but I would say to the public that we've just had the most successful winter we've ever had. We're in a much better tactical position than we've ever been before, we are making a difference," he said. "The Taliban in Oruzgan is totally disrupted, and that's because of the efforts of our people working very effectively with the Afghan National Army and Afghan National Police. We are doing very well in a military achievement sense.

"Now, unfortunately, along the way we will lose soldiers, we are fighting war, people fire weapons in warfare and from time to time we're going to lose someone, but we're making great progress." The death takes the number of Diggers killed in Afghanistan to 27 and the fourth killed in Afghanistan in a fortnight. Lance Corporal Andrew Jones, 25, from Queensland was shot by a rogue Afghan National Army soldier while on guard duty at the Chora Valley patrol base last Monday evening, Australian time. Ms Gillard vowed to hunt down the rogue soldier. A few hours later, Lieutenant Marcus Case, 27, was killed when a Chinook helicopter crashed in southern Afghanistan during a resupply mission.

Lieutenant Case was not part of the Chinook crew but was one of the passengers on board the helicopter. Loading A week before, Sergeant Brett Wood was killed by a roadside bomb. - with Dan Oakes and AAP

