Doctors Without Borders said Wednesday that an international commission has been formally asked to investigate a deadly US airstrike on an Afghan hospital, that killed 22 people, including 12 of the medical charity's staff.
The organisation, known by its French acronym MSF, demanded last week that an independent international commission investigate the hospital attack in the northern Afghan city of Kunduz on October 3.
The International Humanitarian Fact-Finding Commission (IHFFC), an independent mechanism created under international law but which has never before been used, needs one of 76 signatory states to sponsor an inquiry before a probe can begin.
"MSF has been informed that the International Humanitarian Fact-Finding Commission has been activated," the charity said in a statement.
"This is the first step needed to undertake an independent investigation into the attack," it said, adding though that the IHFFC still needed the agreement of the United States and Afghanistan.
Commission vice-president Thilo Marauhn told AFP that the body had sent letters requesting the green light from US and Afghan authorities to begin, "but we have not yet received a response."
President Barack Obama has apologised to MSF and three investigations by the US military, NATO and by Afghan officials are already underway into the attack, which was carried out after the Taliban's brief but bloody capture of Kunduz.
MSF has condemned the attack as a war crime and insists an independent probe is needed since it "cannot rely only on the ongoing internal investigations by parties to the conflict."
"We have received apologies and condolences, but this is not enough," MSF chief Joanne Liu said in the statement.
"We are still in the dark about why a well-known hospital full of patients and medical staff was repeatedly bombarded for more than an hour," she said, insisting: "We need to understand what happened and why."
Beyond determining the circumstances surrounding the Kunduz hospital bombing, MSF insists an investigation by the IHFFC is needed to reaffirm the international laws protecting humanitarian actors in all conflict zones.
"We need to know if the rules of war have changed, not just for Kunduz, but for the safety of our teams working in frontline hospitals all over the world," Liu said.