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.

Gaza's Hamas-run police force said it killed 12 members of an Israeli-backed militia after detaining them early Thursday. Hours earlier, an Israeli- and U.S.

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.