"To date, based on information available, CJTF-OIR assesses that, it is more likely than not, at least 484 civilians have been unintentionally killed by Coalition strikes since the start of Operation Inherent Resolve," the report stated.
The coalition completed an assessment of 47 civilian casualties reports in April, determining that only 16 of them were credible and indicated that 132 unintentional civilian deaths took place.
At the end of the month, the coalition was still investigating 38 reports, according to the release.
The coalition noted that only 0.99 percent of the strikes resulted in reports of possible civilian casualties.
The US-led coalition of 69 members is conducting airstrikes, ground-based and rocket-propelled artillery fire against the Islamic State in Syria and Iraq. The strikes in Iraq are conducted in support of the Iraqi government, but those in Syria are not authorized by the UN Security Council or the government of President Bashar Assad.
