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 controversial aid organization said at least five of its Palestinian volunteer workers were killed in an attack it blamed on Hamas militants.

Israeli firing and airstrikes killed at least 45 Palestinians across the Gaza Strip, many of them near an aid distribution site operated by the U.S.-backed Gaza Humanitarian Foundation on Saturday, local health authorities said.