Days after the United Nations accused Israel of killing 15 humanitarian workers in Gaza, officials who recovered the bodies or carried out the autopsies said some of the rescue workers were shot multiple times before being buried in a mass grave.

The Palestine Red Crescent Society, which had eight of its members killed and carried out the recovery mission, said that nearly all 15 bodies showed gunshot wounds, according to a spokeswoman, Nebal Farsakh. One paramedic was found with his hands and feet tied toward his body, Ms. Farsakh said.

“My colleagues were shot; the bodies who were retrieved, many of them have multiple gun shots. We found all of them thrown in a mass grave, the bodies were put next to each other and covered with sand,” said Ms. Farsakh in a telephone interview from Ramallah.

The deaths of the aid workers, who first went missing on March 23, have drawn international condemnation in recent days.

On that day, in the southern Gaza city of Rafah, ambulances and a U.N. vehicle came under attack from Israel’s military, then went silent. On Sunday, rescue teams found 15 bodies, most in a shallow mass grave along with their crushed ambulances and the vehicle marked with the U.N. logo. The United Nations, which is typically cautious about assigning blame, accused Israel of killing them.

An Israeli military spokesman, Lt. Col. Nadav Shoshani, said on X on Monday that nine of those killed were Palestinian militants. He said Israeli forces “did not randomly attack” an ambulance, but that several vehicles “were identified advancing suspiciously” without headlights or emergency signals toward Israeli troops, prompting them to shoot.