Israel formally acknowledged on Wednesday that its military was responsible for the deadly strikes on an aid convoy in the Gaza Strip that killed seven workers from the charity group World Central Kitchen, calling it “a grave mistake.”

“It was a mistake that followed a misidentification, at night, during the war, in a very complex condition,” the Israeli military chief of staff, Lt. Gen. Herzi Halevi, said in a video. “It shouldn’t have happened.”

The World Central Kitchen workers — a Palestinian, an Australian, a Pole, three Britons and a dual U.S.-Canadian citizen — were traveling in clearly marked cars after leaving a warehouse in Deir al Balah, in central Gaza, when their convoy came under fire late Monday, the organization said in a statement. The Israeli military had been informed of the workers’ movements, the charity said.

The killings drew condemnation from nations around the world, including those of the people killed, and prompted aid agencies to reassess their operations in Gaza. World Central Kitchen, which was founded by the renowned chef José Andrés, said on Tuesday that it was suspending its operations in Gaza.

Earlier on Tuesday, Prime Minister Benjamin Netanyahu said on social media that Israel “deeply regrets the tragic incident.” General Halevi said that an independent body would investigate the killings, and that the military would learn from the conclusions and share the findings with World Central Kitchen.

“Israel is at war with Hamas, not with the people of Gaza,” General Halevi said. “We are sorry for the unintentional harm to the members of the W.C.K. We share in the grief of the families, as well as the entire World Central Kitchen organization, from the bottom of our hearts.”