DEIR AL-BALAH, Gaza Strip — At least 85 Palestinians were killed while trying to reach food at locations across Gaza on Sunday, the territory’s Health Ministry said, on the deadliest day yet for aid-seekers in more than 21 months of war.

There was new alarm as Israel’s military issued evacuation orders for areas of central Gaza, one of the few areas where it has rarely operated with ground troops and many international organizations trying to distribute aid are stationed.

One aid group said several groups’ offices were told to evacuate immediately.

The largest death toll was in devastated northern Gaza, where living conditions are dire.

At least 79 Palestinians were killed while trying to reach aid entering through the Zikim crossing with Israel, said Zaher al-Waheidi, head of the Health Ministry’s records department. The U.N. World Food Program said 25 trucks with aid had entered for “starving communities” when it encountered massive crowds that came under gunfire.

A U.N. official, speaking on condition of anonymity, said Israeli forces opened fire toward the crowds that tried to take food from the convoy. Footage taken by the U.N. and shared with The Associated Press showed Palestinians running as the sound of automatic gunfire could be heard.

“Suddenly, tanks surrounded us and trapped us as gunshots and strikes rained down. We were trapped for around two hours,” said Ehab Al-Zei, who had been waiting for flour. “I will never go back again. Let us die of hunger, it’s better.”

Nafiz Al-Najjar, who was injured, said tanks and drones targeted people “randomly,” and he saw his cousin and others shot dead.

Israel’s military said soldiers had shot at a gathering of thousands of Palestinians in northern Gaza who posed a threat, and it was aware of some casualties.

But it said the numbers reported by officials in Gaza were far higher than its initial investigation found.

The military accused Hamas militants of endangering civilians. More than 150 people were wounded overall, with some in critical condition, hospitals said.