U.S. President Joe Biden said late Tuesday that he was “angry and heartbroken” after an Israeli airstrike in Gaza killed seven staff members of the aid group World Central Kitchen.

“They fed hungry civilians during the war. They were brave and selfless. Their deaths are a tragedy,” Biden said in a statement.

The U.S. leader said Tuesday’s attack was not an isolated incident and that Israel “did not do enough to protect aid workers trying to provide urgently needed help to civilians.”

“The United States will continue to do everything in its power to provide humanitarian assistance to Palestinian civilians in Gaza through all available means,” Biden said. “I will continue to urge Israel to do more to facilitate this assistance. As part of the hostage deal, we are Work hard to push for an immediate ceasefire.”

World Central Kitchen said it immediately suspended its humanitarian work in the region following the attack.

The charity said in a statement that it had completed the task of delivering 100 tons of food aid to the Deir al-Balah warehouse and that a convoy of two armored vehicles bearing the organization’s logo was leaving the scene when the attack occurred.

World Central Kitchen stated that the organization had coordinated the operation with the Israeli military in advance.

Israeli Prime Minister Benjamin Netanyahu admitted that the country’s military had carried out “unintentional attacks…” on innocent people.

“Unfortunately, a tragic incident occurred over the past day in which our forces inadvertently harmed non-combatants in the Gaza Strip,” Netanyahu said in a video statement.

“This happens in war. We are conducting a thorough investigation and are in contact with governments. We will do everything we can to prevent it from happening again.”

The aid group said the victims included a Palestinian, Australian, Polish, British citizens and a dual U.S.-Canadian citizen.

The Palestinian Red Crescent said it recovered seven bodies on Tuesday in a “painstaking operation that lasted several hours” and that they were taken to hospital in preparation for evacuation through the Rafah crossing in southern Gaza.

World Central Kitchen CEO Erin Gore called the attack “inexcusable.”

“This is an attack not only on WCK, but on humanitarian organizations that emerge in the most dire situations where food is used as a weapon of war,” Gore said.

WCK founder Jose Andres said on social media that he was “heartbroken and saddened” after “losing several of our brothers and sisters in the IDF attacks on Gaza.”

“The Israeli government needs to stop this indiscriminate killing,” Andres said. “It needs to stop restricting humanitarian aid, stop killing civilians and aid workers, and stop using food as a weapon. No more innocent lives will be lost. Peace starts with our common humanity. It needs to start now.”

White House press secretary Karine Jean-Pierre said U.S. President Joe Biden called Andres to express his “deepest condolences” and said “he grieves with the entire World Central Kitchen family.”

The group began using the sea route to deliver much-needed food to Gaza after humanitarian groups complained that their truck loads were being intercepted by the Israeli military and that they were unable to safely access areas where people needed help.

Maj. Gen. Daniel Hagari, the IDF’s chief spokesman, said on Tuesday that he had spoken to Andres and expressed the military’s “deepest condolences.”

Hagari said what happened and how it happened was being investigated “at the highest levels” in Israel.

“The IDF has been working closely with the World Central Kitchen over the past few months to assist them in their noble mission of providing food and humanitarian assistance to the people of Gaza,” Hagari said.

“WCK also came to help the Israelis after the October 7 massacre. They were one of the first NGOs to come here,” Hagari said. “WCK’s work is vital. They are humanity’s front line.”

U.N. humanitarian chief Martin Griffiths said on Tuesday he was “outraged” by the attack and called the perpetrators’ actions “indefensible.”

“All this talk of a ceasefire, but this war still takes the best from us,” Griffiths said in a statement.

Prime Minister Anthony Albanese confirmed the death of Australian aid worker Lalzawmi “Zomi” Frankcom on Tuesday and said the government wanted “full accountability”.

“This is a human tragedy that should never have happened and is completely unacceptable,” Albanese told reporters.

Albanese said humanitarian workers and all innocent civilians “need to be protected.”

Polish Foreign Minister Radoslaw Sikorski said on social media that he asked the Israeli ambassador to Poland for an urgent explanation. Sikorski also expressed his condolences to the families of the killed Polish workers and to all civilian victims in the Gaza Strip.

British Foreign Secretary David Cameron said on Tuesday that the British government was working to verify reports that British nationals had died during the strike.

“These people are working hard to deliver life-saving assistance to those who desperately need it,” Cameron said in a statement. “It is vital that humanitarian workers are protected and able to carry out their work.”

EU foreign policy chief Josep Borrell condemned the attack and called for an investigation.

“Despite calls from all sides to protect civilians and humanitarian workers, we are seeing new casualties of innocent lives,” Borrell said.

According to Israeli statistics, Hamas launched an attack on Israel on October 7, killing 1,200 people and leading to the capture of about 250 hostages. After that, Israel launched an operation to eliminate Hamas.

Israel’s counteroffensive in Gaza has killed more than 32,900 people, two-thirds of them women and children, according to the Hamas-controlled Gaza Health Ministry. The Israeli military said a third of those killed were militants.

Information for this report was provided in part by The Associated Press, Reuters and AFP.