US President Barack Obama has apologised to Medecins Sans Frontiers for the U.S. air attack that hit the group's medical clinic in Afghanistan
The aid agency is seeking to invoke a never-used independent body to investigate the bombing which killed 22 people.
The International Humanitarian Fact-Finding Commission (IHFFC) was set up in 1991 under the Geneva Conventions.
MSF is calling the attack a war crime but chair of the US Senate Armed Services Committee, Senator John McCain, says that's an insult.
Our US correspondent Kate Fisher reports
IN:"MSF says..."
OUT: SOC
DUR: 49 seconds