The humanitarian group, Doctors Without Borders (MSF), has blamed the US for an airstrike on Saturday that killed at least 19, 12 medical staff members and seven patients including three children, and injured 37.

Photos of damage done by bombing of #MSF #Kunduz hospital + staff treating patients in parts still standing ©MSF pic.twitter.com/hKOBIyLttI

— Doctors w/o Borders (@MSF_USA) October 3, 2015

President Obama expressed his “deepest condolences” to those killed and injured and said the Department of Defense has launched a full investigation, but MSF executive director Jason Cone tweeted in response, “condolences won’t bring back 12 @MSF dead colleagues. We need answers & independent investigation.”

MSF officials, who provided the US military with their GPS coordinates when they set up the compound, say the aerial bombardment continued after they notified US and Afghani officials the compound was under attack.

US officials confirm that an AC-130 gunship was in the area, to defend U.S. special operations troops on the ground. Afghan officials claimed helicopter gunships returned fire from Taliban fighters who were hiding in the facility, though MSF denies there were any Taliban in the facility at the time. AP video footage of the burned out compound after the attack showed automatic weapons on windowsills.

Afghan government troops had been fighting Taliban, with US air support and advisers in the Kunduz area for about six days when the accident occurred. The hospital had treated 394 before the attack, and there were approximately 105 patients and 80 MSF staff in the hospital at the time of the attack.

The AC-130U is a C-130 Hercules cargo plane armed with a 25-mm Gatling gun, a 40-mm cannon and a 105-mm cannon, according to the Boeing website.