KHAN YOUNIS, Gaza Strip (AP) — Israel said Wednesday that it will allow Egypt to deliver limited quantities of humanitarian aid to the Gaza Strip. The first crack in a punishing 10-day siege on the territory came one day after a deadly blast at a Gaza City hospital killed hundreds and put immense strain on Gaza doctors treating the many wounded as medical supplies ran out.

The announcement to allow water, food and other supplies came as rage over Tuesday night’s blast at al-Ahli Hospital spread across the Middle East, and as United States (US) President Joe Biden visited Israel in hopes of preventing a wider conflict in the region.

There were conflicting claims of who was responsible for the explosion. Hamas officials in Gaza quickly blamed an Israeli airstrike, saying nearly 500 were killed. Israel denied it was involved and released a flurry of video, audio and other information that it said showed the blast was instead due to a rocket misfire by Islamic Jihad, another militant group operating in Gaza. Islamic Jihad dismissed that claim.

The Associated Press has not independently verified any of the claims or evidence released by the parties.

Israel shut off all supplies to Gaza soon after Hamas militants rampaged across communities in southern Israel on October 7. The al-Ahli carnage threw the siege’s impact into sharp relief.

Hundreds of wounded were rushed to another hospital, nearly out of supplies and fuel for its generators, and doctors performed surgery on the floors, often without anaesthesia.

Biden said Egypt’s president agreed to open the crossing and, to begin with, to let in 20 trucks with humanitarian aid. If Hamas confiscates aid, “it will end,” he said. White House officials said the aid would flow as early as Friday, once the roads are patched.

At Rafah crossing, Gaza’s only connection to Egypt, lines of trucks with aid have waited for days to enter. But the facility has only a limited capacity. Egypt must still repair the road across the border that was cratered by Israeli airstrikes.

Supplies will eventually go in under supervision of the United Nations, Egyptian Foreign Minister Sameh Shoukry told Al-Arabiya TV. He did not specify the number of trucks. Asked if foreigners and dual nationals seeking to leave would be let through, he said: “As long as the crossing is operating normally and the (crossing) facility has been repaired.”

Israeli Prime Minister Benjamin Netanyahu’s office said the decision was approved after a request from Biden. It said Israel “will not thwart” deliveries of food, water or medicine from Egypt, as long as they are limited to civilians in the south of the Gaza Strip and don’t go to Hamas militants. The statement made no mention of badly needed fuel.

Palestinian rocket attacks on Israel resumed Wednesday after a 12-hour lull, and Israeli strikes on Gaza continued, including on cities in the south that Israel had described as “safe zones” for civilians.

In his brief visit, Biden tried to strike a balance between showing US support for Israel, while containing growing alarm among Arab allies. Upon his arrival, Biden embraced Netanyahu — and expressed concern for the suffering of Gaza’s civilians.

Biden said the hospital blast appeared not to be Israel’s fault, and he cautioned Israelis not to allow outrage over the deadly Hamas attack to consume them.

Jordanian Foreign Minister Ayman Safadi warned that the war was “pushing the region to the brink.” After the hospital blast, Jordan cancelled a meeting between Biden, Jordan’s King Abdullah II and the Palestinian and Egyptian presidents.

The Israeli military held a briefing Wednesday morning laying out its case for why it was not responsible for the explosion at the al-Ahli Hospital.

Israeli military spokesman Rear Adm. Daniel Hagari said it was not firing in the area when the blast occurred. He said Israeli radar confirmed a rocket barrage was fired by the Palestinian militant Islamic Jihad from a nearby cemetery at the time of the blast, around 6:59 pm. Independent video showed one rocket in the barrage falling out of the sky, he said.

The misfired rocket hit the parking lot outside the hospital, he said. Were it an airstrike, there would have been a large crater there; instead, the fiery blast came from the misfired rocket’s warhead and its unspent propellant, he said.

Hamas called Tuesday’s hospital blast “a horrific massacre,” saying it was caused by an Israeli strike. Islamic Jihad accused Israel of trying “to evade responsibility for the brutal massacre it committed.”