UPDATE: 12.10 p.m. EDT -- U.S. Defense Secretary Ash Carter acknowledged American and Afghan forces have been operating recently in the vicinity of the Doctors Without Borders hospital in Kunduz that was hit by an airstrike with fatal results Saturday.

“While we are still trying to determine exactly what happened, I want to extend my thoughts and prayers to everyone affected,” the defense secretary said. “A full investigation into the tragic incident is under way in coordination with the Afghan government,” Carter said.

UPDATE: 10:55 a.m. EDT -- At least 16 people perished in an airstrike on a Doctors Without Borders trauma center in Kunduz, Afghanistan, NPR reported. Those killed encompassed nine staff members of the nongovernmental organization and seven patients, three of them children.

UPDATE: 5:44 a.m. EDT -- The death toll from a suspected airstrike on a Doctors Without Borders facility in Kunduz, Afghanistan, has risen to nine, with 37 people seriously wounded.

Jason Cone, the executive director of Doctors Without Borders (MSF) U.S., disclosed the updated casualty figures on his Twitter feed, where he also said that the bombing went on for longer than 30 minutes "after American & Afghan military officials in Kabul & Washington first informed of proximity to hospital."

He added that the precise location of the hospital had been communicated to all parties to the conflict "multiple times" in the past few months. He said MSF was "urgently seeking clarity," on how the bombing took place.

In a statement, the organization said that it "condemns in the strongest possible terms the horrific bombing of its hospital in Kunduz full of staff and patients." Of the 37 wounded, 19 are Doctors Without Borders Staff.

In a statement on its Facebook page, the U.S. Embassy in Kabul said: "The U.S. embassy mourns for the individuals and families affected by the tragic incident at the Doctors without Borders hospital, and for all those suffering from the violence in Kunduz. Doctors without Borders performs heroic work throughout the world, including in Afghanistan, and our thoughts and prayers are with their team at this difficult moment."

Original story:

Three staff from the medical nongovernmental organization Doctors Without Borders were killed and 30 remain missing, after an explosion struck the hospital they worked at in the Afghan city of Kunduz early Saturday, which may have been the result of a U.S. airstrike.

There has been fierce fighting in and around Kunduz in recent days, as NATO-backed Afghan forces seek to oust Taliban militants, who seized control of the city Monday. The U.S. military has carried out several airstrikes in the city this week.

In a statement, Doctors Without Borders, which is also known as Médecins Sans Frontières (MSF), said that its trauma center in Kunduz came under “sustained bombing,” and was very badly damaged. At the time of the bombing, the hospital had 105 patients and their caretakers, and more than 80 international and Afghan staff, it added.

“We are deeply shocked by the attack, the killing of our staff and patients and the heavy toll it has inflicted on healthcare in Kunduz,” said Bart Janssens, MSF director of operations.

“We do not yet have the final casualty figures, but our medical team are providing first aid and treating the injured patients and MSF personnel and accounting for the deceased. We urge all parties to respect the safety of health facilities and staff,” he added.

NATO forces spokesman U.S. Army Col. Brian Tribus, said in a statement, cited by the Associated Press, that U.S. forces launched an airstrike in the city at 2:15 a.m. local time (5.45 p.m. EDT Friday).

"The strike may have resulted in collateral damage to a nearby medical facility," he added. "This incident is under investigation."

Doctors Without Borders said that it had treated 394 wounded since fighting began in the city Monday. The organization said it did not have full casualty figures from the incident, as its staff members were treating the wounded.

Taliban spokesman Zabihullah Mujahid told Reuters that U.S. airstrikes targeted the hospital and had killed patients, doctors and nurses. None of its fighters was a patient in the hospital at the time of the attack, the militant group said.