Doctors Without Borders says its hospital in the Afghan city of Kunduz was hit with "aerial bombing raids" every 15 minutes for more than an hour on Saturday morning in an apparent attack by US forces that killed least 19 people, including 12 hospital staff members and three children.

The humanitarian organization — also known as Médecins Sans Frontières, or MSF — said in a statement that the bombing began at around 2:08am local time and lasted until about 3:15am. MSF said its main central hospital building, which houses the intensive care unit, emergency rooms, and physiotherapy ward, was "repeatedly hit very precisely during each aerial raid, while surrounding buildings were left mostly untouched."

"The bombs hit and then we heard the plane circle round," said Heman Nagarathnam, MSF Head of Programs in northern Afghanistan. "There was a pause, and then more bombs hit. This happened again and again. When I made it out from the office, the main hospital building was engulfed in flames. Those people that could had moved quickly to the building's two bunkers to seek safety. But patients who were unable to escape burned to death as they lay in their beds."

MSF said the bombing continued for more than 30 minutes "after American and Afghan military officials in Kabul and Washington were first informed by MSF that its hospital was struck." The organization noted that the US military coalition and Afghan security forces had been provided with the precise GPS coordinates of the hospital as recently as September 29 in order to prevent such an incident from occurring.

US Forces in Afghanistan acknowledged conducting a strike at 2:15am Saturday morning against "individuals threatening the force."

"The strike may have resulted in collateral damage to a nearby medical facility," US Army Colonel Brian Tribus, a spokesman for US forces in Afghanistan said in a statement, adding that the incident is under investigation.

The White House issued a statement from President Barack Obama that offered condolences but stopped short of an apology.

"On behalf of the American people, I extend my deepest condolences to the medical professionals and other civilians killed and injured in the tragic incident at a Doctors Without Borders hospital in Kunduz," Obama said. "The Department of Defense has launched a full investigation, and we will await the results of that inquiry before making a definitive judgment as to the circumstances of this tragedy."

"I have asked the Department of Defense to keep me apprised of the investigation and expect a full accounting of the facts and circumstances," Obama said, adding that the US "will continue to work closely with President Ghani, the Afghan government, and our international partners to support the Afghan National Defense and Security forces as they work to secure their country."

Photo via MSF/EPA

MSF demanded "a full and transparent investigation," and said that "all indications currently point to the bombing being carried out by international Coalition forces."

US Defense Secretary Ash Carter released a statement saying he learned of the incident overnight, and noting that the "area has been the scene of intense fighting the last few days."

"US forces in support of Afghan security forces were operating nearby, as were Taliban fighters," Carter said. "While we are still trying to determine exactly what happened, I want to extend my thoughts and prayers to everyone affected."

Carter called bombing a "tragic incident," and said an investigation is underway in coordination with the Afghan government. "At this difficult moment, we will continue to work with our Afghan partners to try and end the ongoing violence in and around Kunduz," he said.

US and Afghan forces have been struggling to regain control of Kunduz since Taliban fighters seized control of the provincial capital six days ago. Citing civilian testimony, Amnesty International reported "mass murder, gang rapes, and house-to-house searches by Taliban death squads," in Kunduz after the city was captured, with heavy fighting continuing in recent days.

MSF said that since fighting broke out on Monday, the hospital — the only one of its kind in the area — had treated 394 wounded patients. When the bombs fell Saturday morning, MSF counted 105 patients and their caretakers in the hospital, alongside more than 80 international and national MSF staff.

Reached by phone on Saturday morning, Doctors Without Borders spokesman Tim Shenk would neither confirm nor deny reports quoting the Afghan Interior Ministry as saying that 10 to 15 Taliban fighters were hiding in the hospital. Kunduz police spokesman Sayed Sarwar Hussaini told VICE News that Afghan security forces were receiving fire from an area adjacent to the hospital on Saturday.

MSF said wounded patients and staff were treated in a makeshift operating room that was set up in an undamaged part of the hospital. Critically injured patients were reportedly transferred to a hospital in Puli Khumri, a two-hour drive away.

Nicolas Metri, the International Committee of the Red Cross representative in Kabul, said the organization evacuated all of MSF's international staff from Kunduz by plane on Saturday afternoon, including 11 foreign staffers, one Afghan, and one Red Cross doctor.

UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein issued a statement on Saturday calling for "a swift, full and transparent investigation" into the airstrikes.

"This event is utterly tragic, inexcusable, and possibly even criminal," Zeid said. "International and Afghan military planners have an obligation to respect and protect civilians at all times, and medical facilities and personnel are the object of a special protection. These obligations apply no matter whose air force is involved, and irrespective of the location."

According to MFS, the hospital in Kunduz treated more than 22,000 patients in 2014. The organization, which operates in conflict zones around the world, first worked in Afghanistan in 1980. The Kunduz facility was established in 2011.

NATO Secretary General Anders Fogh Rasmussen issued a statement saying he is "deeply saddened by the tragic incident."

"Doctors without Borders perform extraordinary humanitarian work across the world, including in Afghanistan," he said. "They play an important role in helping create the conditions for a better future for the Afghan people. A US investigation into this tragic incident is under way in coordination with the Afghan government."

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