Three soldiers were killed in Oruzgan province by a man said to be wearing a Afghan National Army uniform who opened fire on them while they were resting.
Two more soldiers died in a helicopter crash, reportedly during the aircraft’s landing.
“I believe this is the most losses in combat since the Vietnam War,” said Julia Gillard, who cut short her trip to the Pacific Islands Forum in the Cook Islands to return to Canberra.
“This is news so truly shocking that it is going to feel for many Australians that like a physical blow.
“If we are feeling that then it is hard to imagine what the families of these five men are feeling.
“Their loss is immense, their grief will be sharp and our condolences go to each of them as they are confronted by this news.”