U.S. officials have demanded a “thorough [and] impartial investigation” of the Israel Defense Forces airstrike that killed seven World Central Kitchen workers in Gaza.

“The victims of yesterday’s strike join a record number of humanitarian workers who have been killed in this particular conflict,” Secretary of State Antony Blinken told reporters in Paris. “They have to be protected. We shouldn’t have a situation where people who are simply trying to help their fellow human beings are themselves at grave risk.”

Israel has faced pressure throughout the war with Hamas to allow greater quantities of humanitarian aid into the Gaza Strip. Israeli officials maintain that they allow as much aid as is practical without furnishing supplies that will be seized by Hamas, but the IDF strike on Monday has stoked anger and allegations that Israeli forces have targeted aid workers as part of a policy of denying food to the Gaza Strip.

World Central Kitchen aid workers from Australia, Poland, the United Kingdom, and the Palestinian territories and a dual citizen of the United States and Canada were killed in the strike, while the group is now pausing its operations to discuss the “future of our work,” the organization said in a statement.

“Despite coordinating movements with the IDF, the convoy was hit as it was 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 group’s statement continued.

“Today [World Central Kitchen] lost several of our sisters and brothers in an IDF air strike in Gaza,” World Central Kitchen founder Jose Andres wrote on X. “I am heartbroken and grieving for their families and friends and our whole WCK family.”

Israeli Prime Minister Benjamin Netanyahu acknowledged on Tuesday “a tragic case of our forces unintentionally hitting innocent people in the Gaza Strip” and said that officials would “do everything so that this thing does not happen again.”

The IDF said it is “conducting a thorough review at the highest levels to understand the circumstances of this tragic incident.” IDF spokesman Rear Adm. Daniel Hagari said on Tuesday he had spoken with Andres to express the military’s condolences.