The U.N. human rights office said Wednesday that Israel “may have repeatedly violated” the laws of war by using massive explosives on densely populated areas in the Gaza Strip during the first months of the fighting.

In its report Wednesday, the office highlighted six “emblematic” cases in which the Israel Defense Forces used “explosive weapons with wide area effects” - including 2,000-pound bombs - in civilian neighborhoods in Gaza.

Together, the attacks killed at least 218 people, according to the report. One such attack, on Dec. 2 in Shejaiya, in Gaza City, destroyed 15 buildings and left at least 60 people dead. At the time, the IDF said the target was Wissam Farhat, a senior commander in Hamas’s armed wing.

In five of the strikes, Israel gave no warning, U.N. officials said.

The report comes amid rising scrutiny of Israel’s use of force - and the U.S. role in supplying weapons - in a war that has killed more than 37,000 people in Gaza and left much of the enclave in rubble.

As recently as March, the Biden administration quietly authorized a large transfer of bombs and fighter jets to Israel. And, as The Washington Post reported this week, the Biden administration put pressure on Democratic lawmakers to greenlight a major arms sales to Israel.

But in May, the administration elected for the first time to pause a shipment of thousands of weapons to Israel, including 2,000-pound bombs, amid mounting concern about the country’s plan to expand a military operation in Rafah, a densely packed area of southern Gaza.

On Tuesday, Israeli Prime Minister Benjamin Netanyahu accused the Biden administration of “withholding” weapons and ammunition from Israel - a claim that caused bewilderment among some administration officials.

“We genuinely do not know what he is talking about,” White House press secretary Karine Jean-Pierre told journalists Tuesday. She said one shipment was paused and conversations with Israeli officials were ongoing for its potential release. “Everything else is moving in due process,” she said.

In his video, posted Tuesday on X, Netanyahu said he told Secretary of State Antony Blinken during the official’s recent visit to Israel: “It’s inconceivable that in the past few months, the administration has been withholding weapons and ammunitions to Israel.”

Israeli government spokesman David Mencer, responding to a report that the White House canceled a meeting with Israeli officials over the video, said at a briefing Wednesday that “it’s normal for there to be disagreements, of course, in all partnerships. But the prime minister’s comments speak for themselves.”

Netanyahu is under pressure at home, where dissatisfaction is growing over his handling of the war in Gaza and what critics say is his refusal to commit to a cease-fire deal that would secure the release of 120 hostages still being held in Hamas captivity in Gaza. Thousands demonstrated against Netanyahu and his government in Jerusalem on Monday and Tuesday, demanding early elections and a hostage deal in the first of several protests scheduled for this week.

President Isaac Herzog struck a more appreciative tone about U.S. support to Israel during a meeting with members of the U.S. Congress on Wednesday.

“We are utterly grateful to the United States of America for standing with us in this war. And I’m very grateful to the president of the United States for being here at the beginning of the war and making a clear message on behalf of the American people,” he told the bipartisan delegation led by Rep. Steny H. Hoyer (D-Md.).

Israel said in a statement that it rejected the conclusions of the report by the Office of the High Commissioner for Human Rights about its actions in Gaza. Israel’s envoy to the United Nations in Geneva, Meirav Eilon Shahar, accused the office of “spreading unfounded allegations.”

The group set out to assess whether Israeli attacks in Gaza followed the principles in international law of “proportionality, distinction, precaution and necessity,” Ajith Sunghay, head of the Palestinian territories branch of the U.N. agency, said in a news conference Wednesday.

Under international humanitarian law, armed factions must weigh whether the level of civilian harm an attack might cause is proportional to the military advantage of carrying it out. They are not supposed to launch indiscriminate attacks and should warn civilians ahead of targeting populated areas.

“Our message here is, with these weapons in a densely populated area like Gaza, it would be extremely difficult, if not impossible, to follow those four principles,” Sunghay said.

Sunghay said Israeli military investigators had opened fact-finding probes into five of the six incidents mentioned in the U.N. report - but he called for an independent investigation into each attack and accountability for perpetrators of violations.

The U.N. agency also criticized Palestinian militants Wednesday for embedding weapons or personnel among the civilian population in Gaza.

“However, the mere presence of one commander - or even several fighters, or of several distinct military objectives in one area - does not turn an entire neighborhood into a military objective,” U.N. human rights spokesman Jeremy Laurence said.

He added that states supplying arms to belligerent parties are obligated under international law to ensure the recipient is abiding by the laws of war.

Wednesday’s report, based on open-source information, interviews and other documentation, covers the period from Oct. 7 to Dec. 2. The findings come as the United States weighs whether to release a shipment of the types of heavy bombs mentioned in the report.

Palestinian militants’ repeated launches of unguided rockets into Israel since October also constitute war crimes, the commission said.

Sunghay said Wednesday that he stands by his office’s findings, which he said were based on careful evidence collection and analysis as well as consultation with outside military experts. Palestinians in Gaza are “barely surviving,” said Sunghay, who recently returned from a mission to the enclave.

Here’s what to know

- A merchant vessel was reportedly sunk in the Red Sea after it was attacked by Houthi forces from Yemen. The United Kingdom Maritime Trade Operations agency said “maritime debris and oil” were seen in the last known location of the Liberian-flagged, Greek-owned bulk carrier Tutor. The ship came under attack from a Houthi drone ship on June 12 as it was traveling to Egypt. It is the second ship to have sunk during the Yemeni rebels’ months-long campaign against vessels it views as connected to the United States, Israel or the war in Gaza.

- The Rafah crossing between Israel and Egypt is “completely destroyed,” Israeli media reported. The IDF razed the crossing last month, trapping Gazans seeking to evacuate from the besieged enclave, and shuttering an important artery for incoming aid. The destruction, reported by correspondents for Israel’s Channel 13 and Israeli Army Radio, could complicate efforts to surge aid to Gazans if a cease-fire deal is reached, and as Israel winds down its operation in Rafah.

- Israel struck two military sites belonging to Syria’s armed forces around the Golan Heights, the Hezbollah-owned Al-Manar TV said Wednesday. The Israeli drone strikes around Quneitra and Daraa in southern Syria killed one officer, the official Syrian state news agency reported. The strike comes amid repeated cross-border attacks along the Israel-Lebanon border.

- Hezbollah will invade northern Israel if the IDF starts a war on the Lebanese border, Hasan Nasrallah, leader of the Lebanese militant group and political party, said in a speech Wednesday. Skirmishes between Hezbollah and the IDF on the border have been simmering for months, threatening to boil over into an all-out war. Nasrallah also warned Cyprus against getting involved; he insinuated that the small Mediterranean country was poised to assist the IDF but did not provide evidence for his claims.

- A French court overturned a ban on Israeli companies attending one of the largest weapons expos in the world. Paris’s Commerce Tribunal ordered that the ban, which was put in place by organizers of the Eurosatory forum at the request of French authorities, should be reversed, according to Patrick Klugman, a lawyer who worked on the legal appeal and who called the ban “discriminatory.”

- At least 37,396 ​​people have been killed and 85,523 injured in Gaza since the war started, according to the Gaza Health Ministry, which does not distinguish between civilians and combatants but says the majority of the dead are women and children. Israel estimates that about 1,200 people were killed in Hamas’s Oct. 7 attack, including more than 300 soldiers, and it says 310 soldiers have been killed since the launch of its military operations in Gaza.

Lior Soroka in Tel Aviv, Suzan Haidamous and Sarah Dadouch in Beirut, and John Hudson in Washington contributed to this report.

previous coverage

• Israel’s air defense caught off guard by Hezbollah’s low-tech drones
• Israel says Rafah attack near completion, in potential shift for war