Israel faces growing international pressure over an air strike which killed seven aid workers for charity World Central Kitchen (WCK) in Gaza. The UK, Poland, Australia, Canada and the US, whose nationals died in the attack, demanded Israel investigate. Humanitarian aid to Gaza is now in doubt, with WCK — one of the main providers of aid to the Strip — suspending its operations. Israeli President Isaac Herzog apologized for the deaths. Three of the killed aid workers were British nationals. A Polish national, an Australian, a Palestinian and a dual US-Canadian citizen were also killed. The IDF has promised an independent investigation into the incident. UK Prime Minister Rishi Sunak spoke to Israeli Prime Minister Benjamin Netanyahu on Tuesday. On the call he described the situation in Gaza as "increasingly intolerable" and "demanded a thorough and transparent independent investigation" into the killing of the aid workers. Sunak added that Israel needed to end restrictions on humanitarian aid and protect civilians, according to a Downing Street statement. White House spokesman John Kirby said he was "outraged" at the strike. US President Joe Biden was "heartbroken", Press Secretary Karine Jean-Pierre told reporters. Polish Foreign Minister Radoslaw Sikorski said he had demanded an independent investigation from Israel Katz, his Israeli counterpart. Canadian Foreign Minister Mélanie Joly said she expected "full accountability" for the killings, adding that strikes on humanitarian personnel were "absolutely unacceptable". "Someone going about providing aid and humanitarian assistance should [never] lose their life," Australian Prime Minister Anthony Albanese said. Netanyahu acknowledged that Israel's forces hit "innocent people" and pledged an independent investigation. "Unfortunately, in the last 24 hours there was a tragic case of our forces unintentionally hitting innocent people in the Gaza Strip," he said. "It happens in war, we check it to the end, we are in contact with the governments, and we will do everything so that this thing does not happen again." WCK — founded by celebrity chef José Andrés — said four days ago that it had served 42 million meals in Gaza. The charity said it would pause its operations in the region immediately. "We will be making decisions about the future of our work soon," the charity said in a statement. It said on March 29 that it had served more than 42 million meals in the Strip, making it one of the main suppliers of aid to Gaza. The charity said that it had dispatched a total of more than 1,700 food trucks to the Strip. The charity added that it had sent close to 435,000 meals by sea to Gaza. According to Cogat, the Israeli Defense Ministry body in charge of civilian policy in the Occupied Palestinian Territories, WCK is responsible for 60% of the non-governmental aid getting into the territory. A second charity, the American Near East Refugee Aid (Anera), which was working closely with WCK, told the BBC it was also freezing its operations in Gaza. Some of the aid workers who were killed have been named as: Lalzawmi "Zomi" Frankcom, an Australian citizen. Damian Sobol, a Polish citizen. Saif Abu Taha, a Palestinian According to the charity, the aid convoy was hit while leaving the Deir Al-Balah warehouse, "where the team had unloaded more than 100 tons of humanitarian food aid brought to Gaza on the maritime route." The convoy was made up of three vehicles, including two that were armored, which clearly displayed the charity's logo. All three were hit during the strike. WCK said it had coordinated the convoy's movements with the IDF. More than 196 aid workers have been killed in Gaza since October, according to the US-funded Aid Worker Security Database, which records major incidents of violence against aid personnel. Not all have been killed in the line of duty. Much of the Gaza Strip has been devastated during the Israeli military operations that began after Hamas gunmen attacked southern Israel on Oct. 7, killing about 1,200 people and seizing 253 hostages. About 130 of the hostages remain in captivity, at least 34 of whom are presumed dead. More than 32,916 people have been killed in Gaza since then, the Hamas-run Health Ministry says. — BBC