Gaza’s health ministry said Israeli fire struck a crowd of people waiting for humanitarian aid at a roundabout in Gaza City on Thursday, killing at least 20 and wounding 150. The Israeli military says it was looking into the reports.

Meanwhile, the death toll from a strike the day before on a crowded shelter in Gaza rose to 12, with over 75 wounded, according to Thomas White, a senior official with the UN agency for Palestinian refugees, known as UNRWA.

The agency did not directly blame Israel, which is the only party to the conflict that has tanks.

The Israeli military said it has “currently ruled out” that the strike was carried out by its aircraft or artillery but was still investigating. It says the building might ha

ve been hit by a Hamas rocket.

The fighting in the southern Gaza town of Khan Younis has isolated its two main hospitals, stranding hundreds of patients and thousands of displaced people inside.

A third hospital was evacuated overnight, White said. Thousands of people rushed to escape farther south in recent days, crowding into shelters and tent camps near the border with Egypt.