Attacks on I.S. group targets by us-led coalition forces have killed 484 civilians since mid-2014.
The operation inherent resolve coalition added 132 civilians to the total in its April report, including 105 who died when a US aircraft dropped a bomb on an is sniper target in West Mosul on march 17.
The bomb inadvertently set off a large cache of explosives, collapsing a building on top of civilians sheltering below.
The US-led task force said, the inherent resolve task force “Takes all reports of civilian casualties seriously and assesses all reports as thoroughly as possible.
It stressed only 0.27 percent of its 21,035 strikes since the operation began had produced “Credible” civilian death reports.
The total reported was still far short of what non-governmental organizations estimate for civilian deaths in the conflict in Iraq and Syria.
Airwars, a journalist collective based in London that compiles data from public sources, estimated more than 3,800 non-combatants were killed since the operations began in august 2014.