Afghan soldier kills Australian comrade
The incidents on Monday brought the number of Australians killed in the conflict to 26 and coincided with the arrival home of the body of Sergeant Brett Wood, who died in a bomb blast in the country a week ago.
The Defence Department said one of the troops, a 25-year-old lance corporal, was shot numerous times by an Afghan National Army (ANA) soldier while they were on guard duty together in the Chora Valley.
Australian Defence Force chief Angus Houston rejected suggestions that the "disturbing" shooting was accidental.
"The fact that multiple shots were fired suggests it was more than that," he said.
"We're obviously going to take a very close look at how this occurred, why this occurred and what if anything could have been done to prevent it," Houston told reporters.
"This incident is obviously going to quite rightly raise some very serious questions about the security measures we have in place."
Houston said all Afghan soldiers enrolled in the ANA were vetted by NATO.
"They are the sort of protections we have in place, and obviously we will have another look at those sorts of things as we conduct this investigation," he said.
Prime Minister Julia Gillard defended the nation's role training Afghan soldiers despite the shooting, saying the country had a good relationship with the ANA.
"We have trained and mentored hundreds and hundreds of (ANA) Fourth Brigade soldiers," she said.
"This work is vital to our mission in Afghanistan, indeed we cannot succeed in that mission without doing this training."
The other Australian soldier who died was a lieutenant, 27, who lost his life in a Chinook helicopter crash.
Five soldiers were injured in the incident and evacuated to a medical facility at Kandahar in satisfactory condition.
It is not known if the crash was the result of enemy action.
A total of 214 international troops have been killed in the country so far this year, according to a tally compiled by the independent website icasualties.org. That compares with a total of 711 for last year.
Copyright AFP (Agence France-Presse), 2011