‘Calls for global support for a full inquiry into the U.S. bombing of a charity-run hospital in Afghanistan have gone ignored, according to the head of Medicins Sans Frontieres (MSF) which is mourning the loss of 30 lives in the attack.

Joanne Liu, president of the charity also known as Doctors Without Borders, said the Oct 3. attack in Kunduz in which 13 MSF staff were among the dead could amount to a war crime with signs the hospital was deliberately bombed several times.

But Liu said appeals from MSF to about 76 governments asking for backing for an impartial investigation to clarify what went wrong and prevent any future such tragedy had failed to win support.

“The silence is embarrassing,” Liu told the Thomson Reuters Foundation in an interview on Monday one month after the attack.’

Read more: World ignores calls for inquiry into U.S. bombing of Afghan hospital: MSF