An air strike carried out by the US-led coalition forces which killed at least 19 people in a hospital monitored by Medecins Sans Frontieres on Saturday, in the Afghan city of Kunduz, was "utterly tragic, inexcusable, and possibly even criminal," UN human rights chief officer said.
A hospital belonging to medical aid group, Medecins Sans Frontieres (MSF) in the Afghan city of Kunduz, was heavily damaged and some of its staff members have been confirmed dead after US air strikes were carried out in the area overnight.
"This deeply shocking event should be promptly, thoroughly and independently investigated and the results should be made public," Zeid Ra ad al Hussein said in a statement.
"The seriousness of the incident is underlined by the fact that, if established as deliberate in a court of law, an air strike on a hospital may amount to a war crime."
The Pentagon has ordered a full investigation into the deadly attack.
US Defence Secretary Ash Carter described the incident as "tragic" and noted that US forces were patrolling a nearby area in support of the Afghan Army as the incident took place.
"While we are still trying to determine exactly what happened, I want to extend my thoughts and prayers to everyone affected. A full investigation into the tragic incident is underway in coordination with the Afghan Government."
Kunduz's recent fall to Taliban
The war torn city was captured by Taliban militants on Monday. The takeover is considered to be one of the biggest victories for the militants in their nearly 14-year struggle to regain control of Afghanistan, and a big blow to the Afghan Government. Afghan forces recaptured most of the city but the fighting is still ongoing in several areas.
MSF had treated 394 injured people in Kunduz, since the fierce fighting started in the city on Monday.
Afghan interior ministry spokesperson claimed Taliban fighters were attacking Afghan security forces from an area near the hospital.
"According to our information, the Taliban were hiding in the hospital building and the area around it while attacking our forces," Sediq Sediqqi said.
"We are assessing and evaluating the collateral damage to the medical facility. However, in any case, the safety of the civilians comes first," spokesman added.
Kunduz is Afghanistan’s northern provincial capital. Fighting between Afghan troops and Taliban militants has intensified over the last few days, especially after government forces recaptured most of the city.
Backed by international special forces as well as US air strikes, Afghan government claimed on Thursday that its forces had regained control of Kunduz.
However, there are still some remaining Taliban groups in the city.
The Taliban released a statement after the attack on the hospital in which it accused "barbaric American forces" of carrying out Saturday's air strike on purpose and "killing and wounding tens of doctors, nurses and patients."
Previous US coalition air strike had mistakenly killed 10 Afghan soldiers last July in Helmand Province. Coalition officials initially denied the incident, but later claimed responsibility and announced the matter was under investigation.