Israel’s killing of 15 aid workers in Gaza is “almost certainly a war crime but it’s almost inhuman”, says Martin Griffiths, executive director of Mediation Group International.

“I don’t understand the culture within the [Israeli military] and those platoons for them to be able to do this. It’s a complete inhumane horror,” Griffiths told Al Jazeera. “It’s something to grieve, to observe, to record and to remind.”

Griffiths — former head of the UN’s Office for the Coordination of Humanitarian Affairs (OCHA) — also called on signatory nations of the Geneva Conventions to formally request an independent investigation.

The probe must be “one that most likely should go through the UN Security Council and should then presumably go through the International Criminal Court”, he added.