KABUL, Afghanistan (AFP) — A suspected US air strike on a hospital killed 19 people yesterday in the Afghan city of Kunduz, medical charity MSF said, a bombardment that the UN condemned as “inexcusable, and possibly even criminal”.

Dozens more were seriously wounded at the facility, a key lifeline that has been running “beyond capacity” during fighting that saw the Taliban seize control of the northern provincial capital for several days.

The strike early yesterday left the building engulfed in flames, with photos posted by Doctors Without Borders showing their staff shocked and dazed.

“At 2:10 am (2040 GMT) local time… the MSF trauma centre in Kunduz was hit several times during sustained bombing and was very badly damaged,” the organisation, known by its French initials, said.

“Twelve staff members and at least seven patients, including three children, were killed; 37 people were injured. This attack constitutes a grave violation of international humanitarian law.”

The charity said the bombing continued for more than 30 minutes after American and Afghan military officials were first alerted they were being hit.

“All parties to the conflict, including in Kabul and Washington, were clearly informed of the precise location (GPS coordinates) of the MSF facilities,” the statement added.

NATO conceded US forces may have been behind the strike but has not so far commented on the specific claims of MSF, which has long treated the war-wounded from all sides of the conflict.

“The strike may have resulted in collateral damage to a nearby medical facility. This incident is under investigation.”

The incident has renewed concerns about the use of US air strikes in Afghanistan, a deeply contentious issue in the 14-year campaign against Taliban insurgents.

UN rights chief Zeid Ra’ad Al Hussein called for a full and transparent probe, noting that, “if established as deliberate in a court of law, an air strike on a hospital may amount to a war crime.”

“This event is utterly tragic, inexcusable and possibly even criminal,” he said.

US Defence Secretary Ashton Carter said a “full investigation” is being carried out.

The bombing came after Taliban insurgents overran the northern Afghan city on Monday. It was the first major city to be captured by militants since 2001.

The Afghan defence ministry expressed sadness but in a statement said “a group of terrorists armed with light and heavy weapon… were using the hospital building as a position to target Afghan forces and civilians”.

MSF said some 105 patients and their caregivers, as well as more than 80 international and local MSF staff, were in the hospital at the time of the bombing.

The blackened building was filled with the smell of burning flesh and some bodies were charred beyond recognition, said Qiamudeen, a 31-year-old shopkeeper whose neighbour was killed in the strike.

“I was shocked, emotional and in tears when I reached the hospital,” Qiamudeen, who goes by one name, told AFP.

Another resident said he was anxiously trying to contact six friends, all doctors and nurses at MSF.

“I don’t have any news from them and they may have been killed,” he told AFP.