KABUL, Afghanistan — The medical charity Doctors Without Borders closed its hospital in the Afghan city of Kunduz on Sunday, and charged that a suspected U.S. airstrike that killed 22 people there appeared to have been a war crime.

The closing was a blow to the embattled provincial capital where more than 400 people have been injured in the last week in fighting between Afghan security forces and the Taliban. The group took control of the provincial capital briefly last week.

The Pentagon said there are three investigations into the airstrike, one by the Defense Department, one involving both the United States and Afghanistan, and one by NATO. Pentagon officials have thus far said only that a U.S. airstrike Saturday morning may have caused collateral damage.

Doctors Without Borders said it would be satisfied only with an investigation by an independent, outside authority.

The aid agency called the bombing, which went on for more than an hour, horrifying and said it had informed U.S. and Afghan officials of the hospital’s GPS coordinates before the strike occurred.

Doctors Without Borders said Sunday that the death toll had risen to 22 – 12 staff members and 10 patients, three of them children. Dozens of others were injured.

“Under the clear presumption that a war crime has been committed, (Doctors Without Borders) demands that a full and transparent investigation into the event be conducted by an independent international body,” the organization said in a statement on its website. “Relying only on an internal investigation by a party to the conflict would be wholly insufficient.”

Senior Pentagon officials said the three investigations that have been launched are centered on whether the U.S. military knew the hospital was nearby when an AC-130 gunship opened fire, and whether the hospital was being used by the Taliban to launch attacks.

Thus far, no U.S. or Afghan personnel have been able to gain access to the hospital because the area remains contested, Defense Secretary Ashton Carter said Sunday. He called the situation “confused and complicated.”

The investigations will be “full and transparent,” Carter said. “There will be accountability, as always in these incidents, if that is required.”

U.S. defense officials said small teams of U.S. and Afghan special forces were pinned down by Taliban gunfire Saturday morning near the hospital and called in an AC-130 to pound the area with fire.

The AC-130 Spectre is a heavily armed ground-attack aircraft outfitted with turrets and mounted Gatling-gun style auto cannons that fire rounds powerful enough to rip apart tanks.

Defense officials said that because it was an intense fire exchange with the Taliban, it remains unclear if the AC-130 was responsible for the hospital’s damage or if it came from elsewhere.

But victims inside the hospital said the strikes continued even after the agency contacted military officials and informed them of the hospital’s position.

Gen. John Campbell, commander of U.S. and NATO forces in Afghanistan, has been in constant communication with Carter and Afghan President Ashraf Ghani about the incident. Carter said he said he has not instructed Campbell to halt airstrikes in Afghanistan.

“General Campbell will take whatever actions he thinks are appropriate,” he said. “Right now, he is focused on the investigation and supporting the Afghan security forces.”

Campbell is scheduled to appear before Congress to discuss the campaign in Afghanistan and probably will discuss what happened at Kunduz.

Local and international bodies, including the International Committee of the Red Cross, the United Nations and the public health ministry, have condemned the hospital attack. Afghan forces say Taliban fighters holed up in the facility were firing at government and U.S. forces, but Doctors Without Borders has disputed these claims.

The charity “is disgusted by the recent statements coming from some Afghanistan government authorities justifying the attack on its hospital in Kunduz,” the organization’s general director, Christopher Stokes, said in a statement issued late Sunday. “These statements imply that Afghan and U.S. forces working together decided to raze to the ground a fully functioning hospital – with more than 180 staff and patients inside – because they claim that members of the Taliban were present. This amounts to an admission of a war crime.”

He added that the claim “utterly contradicts the initial attempts of the U.S. government to minimize the attack as ‘collateral damage.’”

For Kunduz residents, basic staples are still hard to come by and many people are afraid to leave their homes. The hospital’s closing is another setback in a week when fighting has left the people waiting for a return to normal.

Wahidullah Mayar, spokesman for the ministry of public health, said the hospital helped reduce the strain on government hospitals, which saw dozens of patients over the last week.

“We have been able to deliver much-needed medical aid to Kunduz but the (Doctors Without Borders) hospital was an important medical site and its damage will have a major impact on the delivery of additional health services to the people of Kunduz,” Mayar said.

Since the hospital opened in 2011, it has earned a reputation among the people of Kunduz and northern Afghanistan as the best facility in the region.

Mohammad Yar, 28, knew the hospital was the best choice when he was asked to transport two young men injured in the ongoing fighting.

“It’s the name everyone in the North knows, so I thought they would be in good hands there,” he said.

Like much of the rest of Kunduz, Yar spent the most of the past week off the streets, so he was unaware of the airstrike on the hospital.

“I only recently heard about it and I can’t believe it,” he said. “They should have come out happy and healthy, that’s why I sent them there.”

Yar has not received any word from the two men since Friday.