NEW DELHI: United States President Barack Obama has promised a “full investigation” into an airstrike that killed 19 people at an MSF-run hospital in Afghanistan on Saturday.

At least 12 Médecins Sans Frontières (Doctors Without Borders) staff and seven patients were killed, when a suspected U.S. airstrike hit the hospital in northern Afghanistan. The US military admitted that a strike targeting the Taliban -- who had taken control of the city of Kunduz earlier in the week -- may have caused "collateral damage".

"The strike may have resulted in collateral damage to a nearby medical facility," Colonel Brian Tribus said in a statement.

"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 in a statement released by the White House.

"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. We will continue to work closely with President [Ashraf] Ghani, the Afghan government and our international partners to support the Afghan National Defense and Security forces as they work to secure their country," the statement said.

The UN called the strikes "inexcusable and possibly even criminal" with Secretary General Ban Ki Moon promising a thorough investigation. "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," said UN High Commissioner Ra'ad Al Hussein Zeid.

MSF responded to the incident by condemning the suspected US bombing as “horrific.” MSF president Meinie Nicolai described the incident as "abhorrent and a grave violation of international humanitarian law.”

"All indications currently point to the bombing being carried out by international Coalition forces," MSF said. The charity further added that US and Afghan forces had been provided exact coordinates of the hospital facility -- which was bombed overnight in strikes that lasted over an hour.

“MSF wishes to clarify that all parties to the conflict, including in Kabul and Washington, were clearly informed of the precise location (GPS Coordinates) of the MSF facilities in Kunduz, including the hospital,” MSF stated.

Further, the organisation added that the strikes appeared to continue even after MSF contacted US forces. “The bombing in Kunduz 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,” MSF said.

The incident comes as MSF services are needed more than ever, with Afghanistan seeing its heaviest fighting in recent years in the city of Kunduz. Government forces claim that they have retaken strategic points in the city, although local reports indicate that the Taliban is still firmly holding sway in many parts.