The Australian Defence Force (ADF) says its fighter jets may have caused the deaths of up to 18 civilians in a strike on Islamic State (IS) militants in Iraq.
The incident in 2017 was part of the US-led coalition’s bid to retake Mosul.
However, the ADF said it was impossible to “definitively know” whether its forces, another coalition strike or “other actors” killed the civilians.
The deaths were “highly regrettable”, military officials said.
Air Marshal Mel Hupfeld said two Australian F/A-18F Super Hornets had bombed IS militants in a residential area on 13 June 2017, following a request by Iraqi ground forces.
A separate strike by unidentified coalition force took place simultaneously in the same street.
Despite post-strike surveys failing to detect civilian deaths, “credible” reports of casualties later emerged, Air Marshal Hupfeld said.
The allegations were first raised publicly by Airwars – a group monitoring civilian deaths – which suggested up to 34 people had died.
Following an investigation launched in January last year, the ADF determined that between six and 18 civilians were unintentionally killed – a figure based on population density estimates.
“Our pilots and decision-makers involved in the targeting process do everything they can to avoid civilian casualties, but sometimes it is not possible,” he said.
Air Marshal Hupfeld said the Australian strikes had accurately hit their targets and been carried out according to protocol. As a result, no penalties or other actions would be taken.
At least 1,190 civilians have been “unintentionally killed” as a result of coalition air strikes in Iraq and Syria since 2014, the joint force said in a statement on Thursday.
It is still working its way through a list of other allegations.
Air Marshal Hupfeld said any compensation actions would be handled by the joint force’s central command.