The fallout from the American airstrike that hit a Doctors Without Borders trauma hospital early Saturday in Kunduz, Afganistan, continues to get messier.

The incident, during which 12 staff members from the medical charity and 10 patients were killed, was initially described by an American spokesman as a byproduct of “collateral damage.” An early version of the events asserted the hospital had been hit by airstrikes in response to a Taliban threat against American forces nearby. Afghan representatives also charged the hospital with harboring Taliban fighters, whom they say were firing from the facility.

Médecins Sans Frontières (MSF), the French name for the organization, strongly denies this charge and left the city Sunday. The United Nations and other groups have condemned the deadly episode, which MSF has characterized as “a war crime.”

On Monday, General John Campbell, who is the top commander in Afghanistan, clarified the American position during a briefing at the Pentagon.

“We have now learned that on October 3rd, Afghan forces advised that they were taking fire from enemy positions and asked for air support from U.S. Forces,” he told reporters.

Campbell added that this revision deviates from earlier reports suggesting “that U.S. forces were threatened and that the airstrike was called on their behalf.” He added that a thorough investigation is ongoing.