Multiple aid workers were killed after a bus was attacked in Gaza on Wednesday night, according to a US-backed humanitarian aid organization which accused Hamas of carrying out the assault.

The group, which has been harshly criticized by the U.N. and other aid providers, said at least five people had died in an attack on one of its buses.

Israel’s use of aid as a weapon of war has provoked outrage. It has prevented essential supplies from entering Gaza. And yet its new effort to distribute aid is also proving deeply controversial. Hamas says it is a front for the idf. International aid organisations have decried it. What is this new network and what is it trying to do?