LONDON - Three British aid workers among the seven killed in an Israeli strike while working for an aid charity in Gaza have been identified as Israel voiced “sincere sorrow” over the deaths.

British victims John Chapman, 57, James "Jim" Henderson, 33, and James Kirby, 47, were part of the World Central Kitchen (WCK) security team.

They died alongside American-Canadian dual citizen Jacob Flickinger, 33, Australian national Lalzawmi "Zomi" Frankcom, 43, who was the leader of the relief team, Polish national Damian Sobol, 35, and Palestinian Saifeddin Issam Ayad Abutaha, 25.

Paying tribute to them, the charity remembered them as “heroes”.

The charity's chief executive Erin Gore said: "These seven beautiful souls were killed by the IDF (Israel Defence Forces) in a strike as they were returning from a full day's mission.

"Their smiles, laughter, and voices are forever embedded in our memories. And we have countless memories of them giving their best selves to the world. We are reeling from our loss. The world's loss."

The World Central Kitchen (WCK) 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.

Announcing the results of a preliminary investigation early Wednesday, IDF spokesperson Lt Gen Herzi Halevi said: “It was a mistake that followed a misidentification - at night during a war in very complex conditions. It shouldn't have happened."

He added that an independent body would conduct a "thorough investigation" which is to be completed in the coming days.

The deaths have caused outrage among Israel’s allies, with Britain summoning the Israeli ambassador to London to express its “unequivocal condemnation”.

Meanwhile, US President Joe Biden has said he was "outraged and heartbroken" by the deaths and called for a swift and transparent investigation.

During a phone call with Israel's prime minister, Rishi Sunak said he was appalled by the killings and demanded a thorough and transparent independent investigation.

A Downing Street spokesperson 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 air strike 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.

"The UK expects to see immediate action by Israel to end restrictions on humanitarian aid, deconflict with the UN and aid agencies, protect civilians and repair vital infrastructure like hospitals and water networks.

"The Prime Minister reiterated that Israel's rightful aim of defeating Hamas would not be achieved by allowing a humanitarian catastrophe in Gaza."

Rishi Sunak did not mention the thousands of innocent Palestinian women and children who have lost their lives since October.

Foreign Secretary Lord Cameron said the killings were "completely unacceptable" as he pressed Israel for "major changes" to ensure the safety of aid workers.

US 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 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 ceasefire as part of a hostage deal. I have a team in Cairo working on this right now."

Labour’s Sir Keir Starmer also called for international law to be upheld as he described the deaths as "outrageous and unacceptable".

The Labour leader said the deaths were "horrifying" and his thoughts were with the families of those killed.

"We condemn this strike. There must be a full investigation and those responsible must be held to account,” he said.

"Humanitarian workers put their lives in danger to serve others. Their deaths are outrageous and unacceptable and it is not the first time aid workers have come under fire in Israel's campaign.”

It is ironic that the leaders of the US and UK did not mention the slaughter of thousands of innocent Palestinian women and children since October 7.