British Foreign Secretary David Cameron, for his part, said that the bombing was "completely unacceptable," and that "Israel must urgently explain how this happened and make major changes to ensure safety of aid workers on the ground."
He was echoed by Australian Foreign Minister Penny Wong who said the death of any aid worker was "outrageous and unacceptable," adding that Canberra was seeking "a thorough and expeditious review" as well as "full accountability for these deaths" from the Israeli government.
US President Joe Biden said he was "outraged and heartbroken" by the killing of seven WCK workers. "Incidents like yesterday’s simply should not happen. Israel has also not done enough to protect civilians," he said on Tuesday.
Ben Saul, the UN Special Rapporteur on the protection of human rights while countering terrorism, has since told Al Jazeera that the Israeli airstrike "could well be a violation of international humanitarian law, under which Israel has a duty not to deliberately target humanitarian workers or their convoys or their relief consignments." He insisted that "under international humanitarian law, if there is a deliberate targeting of any civilian, including humanitarian relief workers, that’s a war crime."