The Israeli military denied that its airstrike near a Rafah camp on Sunday caused the blaze that killed at least 45 displaced civilians, claiming an explosion from a Hamas weapons cache was likely responsible — as new reports allege US munitions were used in the weekend assault.

Israel Defense Forces spokesperson Rear Adm. Daniel Hagari told reporters Tuesday that the Rafah airstrike was aimed at a “closed structure away from the tent,” describing the deaths at the refugee camp as “unexpected and unintended.”

Hagari, however, claimed Israel had used two of the “smallest munitions” possible in the strike, which he said could not have caused the deadly fire.

“Our munition alone could not have ignited a fire of this size,” he said. “We are looking into all possibilities including the option that weapons stored in a compound next to our target, which we did not know of, may have ignited as a result of the strike.”

Sunday’s incident has stirred international outrage against Israel’s operation in Rafah, southern Gaza’s most populous city where more than a million refugees had gathered after fleeing other war-torn parts of the enclave.

Israel has repeatedly denied that its missiles struck the refugee camp, with Hagari noting that a preliminary investigation shows “secondary explosions” at the site.

“We are working to verify the cause of the fire,” Hagari said. “It is still too early to be determined.

“Even when we do find the cause of the fire that erupted, it won’t make this situation any less tragic,” he added.

The Israeli investigation into the fire comes as it was asserted that a US-made GBU-39 small-diameter bomb was likely used in Sunday’s airstrike, according to a CNN analysis.

Several artillery experts who viewed footage of the bombing and its aftermath all attributed the Israeli blast to the GBU-39, which is manufactured by Boeing.

The experts told CNN that the munitions are small, precise, and typically used when trying to minimize “collateral damage.”

The Pentagon and US National Security Council did not comment on what type of ammunition was used in the airstrike.

President Biden had previously said he would not allow certain US weapons to be used in a major operation in Rafah.

White House spokesman John Kirby said Tuesday that Israel’s offensive in Rafah has yet to cross Biden’s “red line,” as he defended Israel’s action and likened it to miscalculations America made in Iraq and Afghanistan when civilians were killed.

“Now, obviously this had tragic results, and obviously that needs to be investigated, and we need to know why even using small-diameter, precision guided munitions, this was able to happen, but we’ll have to let the Israelis get to the bottom of that,” Kirby said.

Along with denying responsibility over the deadly blaze, the IDF refuted claims that it conducted an attack at another refugee camp west of Rafah on Tuesday.

The Hamas-run health ministry claimed an Israeli tank fired at the Al-Mawasi humanitarian zone, killing at least 21 people.

With Post wires