A library image of an Australian Super Hornet (Picture: US Air Force).
The Royal Australian Air Force (RAAF) says it is "possible" that as many as 18 civilians were unintentionally killed during airstrikes over Iraq.
Australia is part of the air coalition, led by the United States, fighting so-called Islamic State in Iraq and Syria.
The coalition says civilians may have died when two Australian F/A-18 Super Hornets bombed a building in Mosul.
RAAF Chief of Joint Operations Air Marshal Mel Hupfeld said: "We have determined that it is possible civilians were unintentionally killed by the coalition during these strikes.
"Any loss of civilian life is highly regrettable and we treat all allegations seriously."
Australia ended air operations over Iraq and Syria in January.
Last May, the British Ministry of Defence admitted that a civilian died as a result of an RAF airstrike.
It was the first confirmed innocent casualty since the UK started bombing IS.
Meanwhile, last year the US military said more than 1,000 civilians had been killed from 2014 until September 2018.