At least 10 were killed and more than 30 injured in the shelling Sunday of a U.N. school in Gaza, the second time a U.N. school has been hit in a week, in the ongoing conflict between Israel and Hamas. The school is in Rafah, a city that borders Egypt and the site of some of Israel’s hardest hits over the weekend.

“We can confirm, tragically again, multiple deaths, multiple injuries," U.N. Relief and Works Agency (UNRWA) spokesman Chris Gunness told Al-Jazeera. "It's an appallingly unacceptable situation. We are an unarmed organization."

The UNRWA school was housing around 3,000 people who had been forced to flee their homes due to Israeli attacks. Most people in the school were from Rafah, where heavy shelling since the collapsed cease-fire Friday left at least 100 people dead, including nine members of the same family.

Gunness told Al-Jazeera he would not speculate if it was Israeli shelling that hit the school.

"Just to be clear, we in UNWRA are not saying it was directly targeted shelling incident in the vicinity of UNWRA school in Rafah. We can confirm multiple deaths, multiple injuries we call on parties to abide by their obligations under international law,” Gunness told Al-Jazeera.

Staff on the ground confirmed it was indeed Israeli shelling but did not say if it was targeted. An Israeli military spokesperson said the attack was under investigation.

“It seems that it was an Israeli airstrike, according to our staff on the ground,” said Adnan Abu Hasna, another UNRWA spokesman. “They shelled near the gate of the school. Multiple people were killed inside and outside the school.” He added an UNRWA staffer was killed in the strikes.

Last week, 16 people died when Israeli shelling hit a U.N. school in Beit Hanoun that had been converted into a shelter for displaced Palestinians. Despite the fact the U.N. said it had communicated the exact coordinates of all the U.N. locations housing refugees to Israel multiple times.

The latest school attack came on the heels of Israeli Prime Minister Benjamin Netanyahu vowing at a press conference Saturday he will “bring back calm and order, and we will continue to operate until this goal is reached no matter how much time it takes.”

Also Sunday, the Israeli army began moving out of Gaza and regrouping near the border. While Netanyahu said the mission in Gaza was far from over, most of the “terror tunnels” had been destroyed. Haaretz reported the “bulk of troops” have been withdrawn from Gaza. However, there has been no official order to end Operation Protective Edge.

The current death toll, the Gaza Health Ministry said, is 1,726, with at least 8,000 injured and more than 450,000 displaced. Sixty-four Israeli soldiers have died in combat, including 2nd Lt. Hadar Golding, who was thought to have been captured in an ambush on Friday.