Julia Gillard, in the Cook Islands, speaks to the media about the five Australian soldiers killed in Afghanistan. Credit:AFP Prime Minister Julia Gillard, who was in the Cook Islands for the Pacific Islands Forum, has cancelled her commitments at the forum and is returning to Australia for briefings on the incidents. ''I believe this is the most losses in combat since the days of the Vietnam War and the battle of Long Tan,'' she told reporters before flying out. ''This is news so truly shocking that it's going to feel for many Australians like a physical blow.'' A visibly emotional Ms Gillard pledged Australia cannot have its war aims dictated by ''even the most grievous of losses'' after the worst bloodshed for Australians in combat in decades.

"We are making progress. I can tell you that, I've seen it with my own eyes when I have visited Afghanistan,'' she said. The names of the three men killed in the first incident have not been released, but they were all based at Brisbane's Enoggera Barracks. They included a 40-year-old lance corporal posted to the 2nd/14th Light Horse Regiment of the Queensland Mounted Infantry. He was on his second tour of Afghanistan and had previously served in Iraq. The second soldier was a 23-year-old private posted to the 6th Battalion Royal Australian Regiment and the third was a 21-year-old sapper posted to the 2nd Combat Engineer Regiment. ''Both these young men were on their first operational deployment,'' Air Marshal Binskin said He said the shooting happened 20 kilometres north of Tarin Kowt. The soldiers were fired on at close range, and while the Australians returned fire, the attacker escaped.

In the second incident, two privates - aged 30 and 23 - died when the International Security Assistance Force helicopter they were travelling in crashed while landing in a northern province at 7.47am AEST. "Australia has lost five men today, they were soldiers who were committed to serving their nation ... I want [the families] to know that the army and the ADF community share their anguish and will continue to support and care for them," Air Marshal Binskin said. "This is a terrible day for all of us." He said Australian security was already higher than the recommended level of force protection outlined by ISAF. He conceded "morale at the moment has taken a hit over this, understandably ... but we remain committed to the mission we have in Oruzgan".

The confirmation followed reports this morning that three ISAF members were killed by a person wearing an Afghan National Army uniform - a "green on blue" attack. Air Marshal Binskin said Defence had some details of the perpetrator of the insider attack, which occurred while the soldiers were relaxing at the end of the day. ''We're currently trying to track him as he's escaped. But I don't want to get into any more details on him at the moment,'' he said. Air Marshal Binskin said he was not sure of the attacker's motives or the events leading up to the shooting. "The reasoning does vary. We're not at the bottom of what it may be in this case but we have been working with ANA [Afghan National Army] in their vetting process and they have been working hard at tightening up their process."

About 1550 ADF troops are deployed in Afghanistan as part of the International Security Assistance Force. The shootings will place more pressure on commanders of the NATO-led coalition in Afghanistan, who have been keen to paint an optimistic picture of the readiness of Afghan National Security Forces to increasingly assume the security lead across their beleaguered nation. There has recently been a rise in ‘‘green on blue’’ attacks in Afghanistan. Two US soldiers were killed in such an attack earlier this week. Retired major general Jim Molan told the ABC yesterday that such attacks could increase as international forces prepared to withdraw by 2014. ‘‘The probability of them increasing is high,’’ he said.

Opposition Leader Tony Abbott said today was "a terrible day for our country and a black day for our Defence Force". Mr Abbott said his thoughts and prayers were with those who had been killed, their families and comrades. "They died in the service of our country, trying to make the world a better place and our country will draw strength from their service and memory." Governor-General Quentin Bryce said the losses over the past 24 hours "signified one of our darkest days".



"I know that Australians everywhere will pause to think of the families left behind, and the colleagues who will feel this tragic loss deeply," Ms Bryce said in a statement.



"These terrible losses will only steel the resolve of those who continue this important work." Up until today Australia had lost 33 soldiers in Afghanistan since February 2002. Most recently, Sergeant Blaine Flower Diddams, of the Special Air Service Regiment, was killed during a small arms engagement with insurgents in July.

According to ISAF, this year more than 30 insider attacks have killed 45 coalition troops, making up about 14 per cent of the overall death toll in the war for 2012.



The commander of NATO forces in Afghanistan, US General John Allen, said last week the causes of the surge in insider attacks were varied, and that Taliban infiltration accounted for about a quarter of the incidents.



A Pentagon assessment last year found serious tensions between the coalition forces and their Afghan counterparts, with relations plagued by cultural clashes and deep mistrust. Last year four Australian soldiers were killed by Afghan troops in two attacks.



In October, three Australian soldiers were killed by an Afghan Army sergeant when he turned a machine gun on them during a parade. The Afghan soldier was immediately shot dead. In another incident in November, an Afghan soldier shot and wounded three Australians. He escaped and remains on the run.



In May, army cook Andrew Jones was shot dead by a rogue Afghan soldier at a patrol base. Loading With Dan Flitton, Agencies