Kabul: Three Australian commandos and a US soldier were killed when a helicopter crashed on Monday in southern Afghanistan, where NATO forces are mounting an ambitious campaign to flush out Taliban militants.
Three other personnel were seriously wounded in the crash in Kandahar province, Australian armed forces chief Angus Houston and Defence Minister John Faulkner said. The chopper was not brought down by enemy fire, they said.
The crash was Australia`s deadliest single incident in the nearly nine-year conflict.
"This is a tragic day for Australia and the Australian Defence Force," Prime Minister Kevin Rudd told Australia`s parliament. "This is a very heavy price to pay."
A NATO spokeswoman in Kabul confirmed that a US soldier was also killed in the incident.
The deaths brought to 278 the number of foreign soldiers killed in Afghanistan this year, according to an news agency tally based on figures kept by the independent icasualties.org website.
Much of southern Afghanistan is blighted by the Taliban insurgency, now in its deadliest phase. US and NATO troops are building up a campaign to flush the militants out of Kandahar city.
"This most dangerous theatre of operations has claimed five Australian lives in just two weeks and it`s with very great sadness that we are here today to inform you of these casualties," Faulkner said.
The crash, which brings Australia`s death toll in Afghanistan to 16, comes two weeks after two soldiers from the country were killed in a bomb blast during a sudden spike in foreign casualties.
Faulkner and Houston pledged to continue the mission to Afghanistan, where Australia has about 1,550 troops in Uruzgan province.
Rudd, who has called the war "unpopular", sent 450 reinforcements last year but has resisted Washington`s calls to provide more.
It was the second helicopter crash to kill NATO troops this month. Taliban militants killed four US soldiers on June 9 when they shot down a helicopter in the southern province of Helmand.
The US military has warned that casualty tolls will inevitably climb during the increased activities as they seek to rout Islamist insurgents.
Kandahar is the birthplace of the Taliban movement and a hotbed of bombings, assassinations and lawlessness.
NATO, US and Afghan soldiers are preparing their biggest operations yet against the Taliban in Kandahar, with total foreign troop numbers set to peak at 150,000 across the country by August.
But the Kandahar operation promises to be a major test of Western military efforts to bring a quick end to the war, facing a shortage of Afghan security forces and scepticism among residents.
This month NATO commander US General Stanley McChrystal said the make-or-break operation would move at a slower pace than initially planned.
Apart from the shortage of Afghan forces, McChrystal said more political work was required to prepare the ground for military operations, to ensure support from Kandahar`s leaders and the local population.