Five children die in Aussie crossfire

It appears the children were caught in the crossfire as members of the Special Operations Task Group came under "heavy fire" from insurgents while the soldiers were checking compounds.

The Australian Defence Force began an investigation into the incident early on Thursday at an undisclosed location in Oruzgan province.

But it will be several weeks before it reports.

Lieutenant-General Mark Evans, the ADF chief of joint operations, said five local children were among those who died as a result of the firefight.

"Current reporting indicates that those killed include a suspected insurgent and, sadly, local nationals, including five children killed and two children and two adults injured," he told reporters.

No Australians were hurt.

Defence Minister Joel Fitzgibbon said the soldiers were operating in a very complex environment.

"(They were) raiding compounds. Our people were under heavy fire," he told ABC radio.

Mr Fitzgibbon expressed his profound regret but was confident Australian troops had done their best to prevent civilian deaths.

"I have overwhelming confidence that our people always act cautiously, responsibly, completely in conformity with their rules of engagement and completely in keeping with their obligations under international law," he said.

"Counter-insurgency campaigns happen within communities and ... the reality is Taliban and other insurgents are known to deliberately use civilians as human shields."