CNN geolocated videos showing tents in flames in the aftermath of the strike on the camp for internally displaced people (IDPs) known as “Kuwait Peace Camp 1.”

In video shared on social media, which CNN geolocated to the same scene by matching details including the camp’s entrance sign and the tiles on the ground, the tail of a US-made GBU-39 small-diameter bomb (SDB) is visible, according to four explosive weapons experts who reviewed the video for CNN.

The GBU-39, manufactured by Boeing, is a high-precision munition “designed to attack strategically important point targets,” and result in low collateral damage, explosive weapons expert Chris Cobb-Smith told CNN.

However, “using any munition, even of this size, will always incur risks in a densely populated area,” said Cobb-Smith, a former British Army artillery officer.

Trevor Ball, a former US Army senior explosive ordnance disposal team member who also identified the fragment as being from a GBU-39, explained to CNN how he drew his conclusion.

“The warhead portion [of the munition] is distinct, and the guidance and wing section is extremely unique compared to other munitions. Guidance and wing sections of munitions are often the remnants left over even after a munition detonates. I saw the tail actuation section and instantly knew it was one of the SDB/GBU-39 variants.”

CNN’s identification of the munition is consistent with a claim made by Israel Defense Forces spokesperson Rear Admiral Daniel Hagari in a briefing about the tragedy on Tuesday. Hagari stated the strike – which he claimed targeted senior Hamas commanders – used two munitions with small warheads containing 17 kilos of explosives, adding these bombs were “the smallest munitions that our jets could use.”

The traditional GBU-39 warhead has an explosive payload of 17 kilos.

Additionally, serial numbers on the remnants match those for a manufacturer of GBU-39 parts based in California – more evidence the bombs were made in the US.

Gaza officials say the death toll from Israeli air strikes on a camp housing displaced Palestinians near Rafah in southern part of the strip has risen to 45.

The enclave’s health ministry on Monday reported 45 people, including 23 women, children and elderly, were killed in the attack and 249 others wounded.

The outgoing official, Stacy Gilbert, served in the State Department’s Bureau of Population, Refugees and Migration.

Gilbert sent an email to staff Tuesday explaining her view that the State Department was wrong to conclude that Israel had not obstructed humanitarian assistance to Gaza, officials who read the letter said.

The cause for resignation is unusual in that it speaks to internal dissent over a hotly disputed report that the Biden administration relied on to justify continuing to send billions of dollars of weapons to Israel.

The report Gilbert objected to was published this month in response to a presidential memo known as NSM-20.

President Biden issued the memo in February after coming under pressure from congressional Democrats concerned about the rising death toll in Gaza. It required the State Department to assess whether Israel’s use of U.S. weapons in Gaza violated U.S. or international humanitarian law and included an examination of whether humanitarian aid had been deliberately obstructed.

The report — the product of weeks of discussion within the State and Defense departments — found that while “aid remains insufficient,” the United States does not “currently assess that the Israeli government is prohibiting or otherwise restricting the transport or delivery of U.S. humanitarian assistance”.

Gilbert, whose views were echoed by the vast majority of aid and humanitarian organizations, said Israel was impeding the aid from reaching civilians in Gaza. Aid flows have continued to be constricted in the weeks since the report was issued. But the report found insufficient grounds to halt aid to Israel.

Along with Paul, a handful of Biden administration officials have resigned since the conflict began in October, including Annelle Sheline, who worked on human rights issues, and Hala Rharrit, one of the department’s Arabic-language spokespeople. Still more have expressed unhappiness with administration policy by sending cables via the internal dissent channel, a process intended to allow diplomats to articulate disagreement without fear of retribution.

After Rharrit resigned, she said that as the months of the conflict progressed, it became more clear that internal discussion about U.S.-Israel policy was unwelcome, unlike almost every other subject during her 18-year career at the State Department.

The Biden administration paused the transfer of some bombs and precision guidance kits to register its concerns over a potential large-scale invasion of Rafah. But it has left most weapons flows untouched and has said Israel’s actions in the crowded border city do not yet cross the president’s “red line” despite the rising death toll and increasing military operations.

Multiple administration officials in press briefings Tuesday described the images out of Rafah as “heartbreaking”, “tragic” and “horrific”. But there was no sign of an impending policy change as a result, because it was an air raid and not a major ground operation.

“We still don’t believe that a major ground operation in Rafah is warranted. We still don’t want to see the Israelis, as we say, smash into Rafah with large units over large pieces of territory. We still believe that, and we haven’t seen that at this point,” White House spokesperson John Kirby told reporters.

“As a result of this strike on Sunday, I have no policy changes to speak to,” he added.

“It just happened. The Israelis are going to investigate it. We’re going to be taking great interest in what they find in that investigation. And we’ll see where it goes from there.”

President Joe Biden earlier this month warned he would stop supplying Israel with offensive weapons such as bombs and artillery shells if it launched a long-promised invasion of Rafah.

The White House has urged Israel against sending forces into Rafah without a clear plan to evacuate civilians safely, because the war has already left tens of thousands of Palestinians dead, and about a million refugees have settled in Rafah after fleeing fighting in northern Gaza.

National security adviser Jake Sullivan last week told reporters there was “no mathematical formula” for assessing Israel’s conduct in Rafah, but officials would look at “whether there is a lot of death and destruction from this operation or if it is more precise and proportional”.

But administration officials stated Tuesday that Sunday’s airstrike, which was the deadliest incident in Rafah since Israel launched an offensive there, did not amount to what the White House has warned against.

“It is still our assessment that what is happening in Rafah and what the [Israeli military] are doing, it is limited in scope,” Pentagon deputy press secretary Sabrina Singh told reporters.

Israel Prime Minister Benjamin Netanyahu described the Rafah fire as tragic and stated Israel is “investigating it thoroughly and will learn from it, as is our policy and longstanding conduct”.

The White House has for weeks urged Israel to do all it can to prevent the deaths of innocent civilians and humanitarian workers in Gaza, where scores of Palestinians are without access to adequate food, water and medicine.

Biden has grown increasingly frustrated with Netanyahu, saying in an interview earlier this year that his handling of the war in Gaza was hurting Israel more than it was helping.

Kirby stated Tuesday that “no civilian casualties is the right number of civilian casualties”, but he acknowledged innocent people are often killed in war.

“There’s not like a measuring stick here or a quota,” he added, when asked if there were a number of civilian deaths that would prompt action from the U.S.

“As we’ve said many times, the right number of civilian casualties is zero.”