United States owes world full and frank explanation on Afghan hospital air strike that killed more than 20

Innocent civilians are inevitable casualties of armed conflict. In a troubled world the senses can be numbed to reports of their death and suffering. But when this results from a violation of an accepted rule of war and international law, many are rightly outraged.

Such feelings are widely shared in the aftermath of an apparent US air strike on an Afghan hospital that killed more than 20 staff and patients. The grim toll, including three children and 40-odd people injured, is bad enough.

On reflection, two things seriously compound the tragic blunder. The air raid continued for more than an hour despite repeated calls to US and Afghan authorities warning that it was a hospital that was under attack in the embattled strategic northern city of Kunduz.

And when it was over and the remaining medical personnel had rendered emergency treatment to survivors, the international medical charity Doctors Without Borders (MSF) announced that it was withdrawing staff from the hospital, the only free facility in the northeastern region that can deal with major war injuries.

That makes life even more precarious for people caught between the Taliban and government troops in a battle for control of Kunduz. At the time of the bombing some 100 patients and their caregivers and more than 80 international and local MSF staff were in the hospital.