Israel faced growing global condemnation as three British aid workers killed in one of its airstrikes in Gaza were named Wednesday.

World Central Kitchen (WCK) confirmed the British victims as John Chapman, 57, James "Jim" Henderson, 33, and James Kirby, 47, who were working for the charity’s security team, were among seven of its staff killed.

The team’s leader, Lalzawmi "Zomi" Frankcom, 43, an Australian national, also died, along with U.S. Canadian dual citizen Jacob Flickinger, 33, Polish national Damian Sobol, 35, and Palestinian Saif Issam Abu Taha, 25.

According to The Times, Chapman was a former Royal Marine from Cornwall who was due to leave Gaza on Monday, while The Sun said he had served in the Special Boat Service, the special forces unit of the Royal Navy.

Henderson was also a former Royal Marine, according to The Daily Telegraph, while Kirby is also believed to be a military veteran.

WCK’s chief executive Erin Gore described the victims as "the heroes of World Central Kitchen."

U.S. President Joe Biden said he was "outraged and heartbroken" by the deaths and said he had spoken to WCK founder Jose Andres.

"This is not a standalone incident," he said. "This conflict has been one of the worst in recent memory in terms of how many aid workers have been killed.

"This is a major reason why distributing humanitarian aid in Gaza has been so difficult – because Israel has not done enough to protect aid workers trying to deliver desperately needed help to civilians."

"Incidents like yesterday’s simply should not happen," he added.

He said an Israeli investigation "must be swift, it must bring accountability and its findings must be made public."

"I will continue to press Israel to do more to facilitate that aid," he said. "And we are pushing hard for an immediate cease-fire as part of a hostage deal. I have a team in Cairo working on this right now."

The convoy was hit as it was leaving the Deir al-Balah warehouse, where the team had unloaded more than 100 tonnes of humanitarian food aid taken to Gaza on the maritime route, the charity said.

WCK immediately suspended operations in the region.

Israeli Prime Minister Benjamin Netanyahu confirmed Israeli forces were behind the "unintended strike" on Tuesday.

During a phone call with Netanyahu, British Prime Minister Rishi Sunak said he was appalled by the killings and demanded a thorough and transparent independent investigation.

A Downing Street spokesman said: "The prime minister spoke to Israel’s prime minister, Benjamin Netanyahu, this evening.

"He said he was appalled by the killing of aid workers, including three British nationals, in an airstrike in Gaza yesterday and demanded a thorough and transparent independent investigation into what happened."

"The prime minister said far too many aid workers and ordinary civilians have lost their lives in Gaza and the situation is increasingly intolerable," they added.

"The U.K. expects to see immediate action by Israel to end restrictions on humanitarian aid, deconflict with the U.N. and aid agencies, protect civilians and repair vital infrastructure like hospitals and water networks," the Downing Street said.

"The prime minister reiterated that Israel’s rightful aim of defeating Hamas would not be achieved by allowing a humanitarian catastrophe in Gaza," it added.