The United States called Thursday on Israel to be "transparent" over a strike on a U.N. school in Gaza where thousands of people had sought refuge, including on whether children were killed.

"The government of Israel has said that they are going to release more information about this strike, including the names of those who died in it. We expect them to be fully transparent in making that information public," State Department spokesperson Matthew Miller told reporters.

The Israeli military admitted hitting the school run by URNWA, the U.N. agency for Palestinian refugees, in the Nuseirat refugee camp in central Gaza, claiming Hamas fighters were hiding inside.

In a gaffe, Miller first said Israel "has a right to try and target those civilians" when speaking of the attack on the school. The remarks were quickly corrected.

"Israel has a right to try and target those civilians, but they also have the obligation to minimize civilian harm, and take every step possible to minimize civilian harm," he said. "So that's why we're pressing the government of Israel, and the IDF, to be completely transparent about what happened here."

Asked by about the spokesperson's remarks, the State Department said Miller misspoke, and that he intended to say "Hamas" rather than "civilians."

Miller said Israel told the U.S. essentially what they have said publicly.

"And this is their claim, that they were targeting 20 to 30 members of Hamas and other militant groups, that they used a precision strike to target only one part of the building without hitting areas where civilians were sheltering," he noted.

"At the same time, we've seen the reports on the ground, we've seen the videos from the ground, we've seen the claims that 14 children were killed in the strike, and certainly if that is accurate, that 14 children were killed, those aren't terrorists."

Miller could not confirm if U.S. weapons were used in the strike, though multiple media outlets reported, based on analysis of video from the scene, that they were used.

Authorities at Al-Aqsa Martyrs Hospital said that the attack left at least 40 people dead and dozens of others injured when it struck the facility without any prior warning to the 6,000 people who were sheltering. They said the death toll may rise.

"Another horrific day in Gaza. Another UNRWA school turned shelter attacked. This time in Nuseirat, in the Middle Areas, hit overnight by the Israeli Forces without prior warning to the displaced or UNRWA," Philippe Lazzarini, the head of the UNRWA, wrote on social media platform X.

"Attacking, targeting or using U.N. buildings for military purposes are a blatant disregard of International Humanitarian law. U.N. staff, premises and operations must be protected at all times," he added.

The Israeli military admitted hitting the UNRWA school in the Nuseirat refugee camp in central Gaza, claiming Hamas fighters were hiding inside.

Lazzarini said the U.N. was "unable to verify claims" by Israel that Hamas members were inside the school.

Israel's relentless strikes have killed at least 36,654 people in Gaza, mostly women and children, and injured over 83,000 others, according to local health officials.

The war started after Hamas's Oct. 7 cross-border attack on Israel, which resulted in the deaths of nearly 1,200 people, according to Israeli figures.

Vast tracts of Gaza lay in ruins amid a crippling blockade of food, clean water and medicine.

Israel is accused of genocide at the International Court of Justice, whose latest ruling has ordered Tel Aviv to immediately halt its operation in the southern city of Rafah, where more than 1 million Palestinians had sought refuge from the war before it was invaded on May 6.