US security forces says air strikes have killed 45 people in March.
The Pentagon says investigations conducted during the month of March reveal that coalition air strikes killed 45 civilians, mostly in and around the city of Mosul.
In a statement released on Sunday, the Pentagon says in each incident "all feasible precautions were taken", but the strikes still resulted in "unintentional" loss of civilian life.
The Pentagon acknowledges at least 362 civilians have been killed by coalition strikes in Iraq and Syria since the start of the air campaign against the Islamic State group in 2014.
Activists and monitoring groups put the number much higher, saying coalition strikes have killed more than 3000 civilians in Iraq and Syria since then, according to Airwars.
The US launched a campaign of air strikes against IS in August of 2014 after it overran Mosul and swaths of Iraq's north and west.