Amid reports of mounting civilian casualties from airstrikes carried out by the United States-led coalition in Iraq and Syria, the White House acknowledged that it had not followed the “near-certainty” standard to minimize civilian casualties in the Islamic State group-controlled territories, according to a Yahoo News report published Tuesday.

The report comes just days after coalition warplanes struck grain storage facilities, mills and silos in northern and eastern Syria, reportedly killing an unknown number of civilians. On Sept. 23, at least seven civilians, including women and children, were also killed in airstrikes in Idlib province in Syria, prompting harsh criticism from many human rights groups.

Caitlin Hayden, spokesperson for the U.S. National Security Council, told Yahoo News that the “near certainty” standards -- outlined by President Barack Obama last year to minimize the risk of civilian deaths in drone strikes -- would apply “only when we (the U.S.) take direct action outside areas of active hostilities,” adding that the current situation in Iraq and Syria did not fit the description.

However, she added, the joint military operations in Iraq and Syria “are being conducted consistently with the laws of armed conflict, proportionality and distinction.”

Harold Koh, who served as the State Department’s legal adviser during Obama’s first term, told Yahoo News that the lack in clarity of standards being used to authorize airstrikes creates a “grey zone” in the conflict.

“If we’re not applying the strict rules to Syria and Iraq, then they are of relatively limited value,” Koh reportedly said.

While the new standards being used for airstrikes in Iraq and Syria have not been spelt out, a former unnamed White House official told Yahoo News that the policy provided more discretion to the U.S. Central Command to select targets without having to seek prior approval from the administration.