Smoke rises from Israeli raids on October 13, in Gaza City, Gaza. (Ahmad Hasaballah/Getty Images)

(CNN) — Palestinian officials say hundreds are likely dead after a deadly blast hit a Gaza hospital on Tuesday, as humanitarian concerns mount over Israel’s deprivation of food, fuel and electricity to the enclave’s population.

Al-Ahli Baptist Hospital was sheltering thousands of displaced people when it was bombed Tuesday, the Palestinian Health Ministry said in a statement. Many victims are still under the rubble, it added.

Palestinian officials blamed ongoing Israeli airstrikes for the lethal incident. But the Israel Defense Forces denied any involvement in the hospital attack, blaming instead a “failed rocket launch” by the Palestinian Islamic Jihad group.

“Intelligence from multiple sources we have in our hands indicates that Islamic Jihad is responsible for the failed rocket launch which hit the hospital in Gaza,” the IDF posted to its Telegram account.

Gaza has been under siege by Israel for more than a week, in response to the deadly incursion by Hamas, the Islamist militant group that controls the coastal enclave, home to 2.2 million people. Hospitals meanwhile are struggling to tend to the wounded across the territory, operating with shortages of electricity and water.

Amid growing international pressure to address the crisis, US President Joe Biden will travel to Israel on Wednesday, an extraordinary wartime visit that follows intense efforts by Secretary of State Antony Blinken across the Middle East.

Palestinian Authority President Mahmoud Abbas canceled a planned meeting with US President Joe Biden after the hospital attack, saying he would instead travel back to Ramallah for an urgent meeting of the Palestinian leadership.

Vital humanitarian aid is meanwhile piling up at Gaza’s shuttered border, despite diplomatic efforts to open a corridor from Egypt. The United Nations and other officials have said they need assurance of safe passage for any potential aid convoys.

Israeli and US officials on Tuesday said humanitarian aid would be allowed into southern Gaza, but Israel’s national security adviser warned it would be stopped if Hamas intervened. “Intense discussions” are still underway regarding the movement of aid, UN spokesman Stephane Dujarric said on Tuesday.

On Tuesday, Israel’s National Security Minister Itamar Ben-Gvir said the only things that should be entering Gaza “are hundreds of tons of explosives from the Air Force, not an ounce of humanitarian aid” until Hamas releases hostages, he wrote on Telegram.

Hospitals under siege

The Al-Ahli Baptist Hospital in the center of Gaza City was sheltering thousands of displaced people who were forcibly evacuated from their homes by the occupation, according to the Palestinian Ministry of Health in Gaza.

The bombing was described by the Palestinian Foreign Ministry as a “cold-blooded massacre.”

The hospital attack will “forever remain a stain on the conscience of humanity that has been witnessing the horrors committed against the Palestinian people without taking action to stop it,” the statement read.

Tal Heinrich, a spokesperson for the Israeli prime minister, told CNN Tuesday that “IDF does not target hospitals, we only target Hamas strongholds, arms depots and terror targets.

It comes as Palestinian health officials warn that displaced people continue to be struck by Israeli shelling.

Over a week of Israeli bombardment has killed at least 3,000 people, including 1,032 girls and 940 boys, and wounded 12,500 in Gaza, the Palestinian Ministry of Health said Tuesday. Casualties in Gaza over the past 10 days have now surpassed the number of those killed during the 51-day Gaza-Israel conflict in 2014.

On Tuesday, Israeli strikes on two densely populated refugee camps and an UNRWA school housing displaced people in central Gaza killed at least 18 people and injured scores, Palestinian officials said.

The IDF confirmed that high-level Hamas commander Ayman Nofal was killed in the airstrikes in Gaza on Tuesday.

In the occupied West Bank at least 61 people have been killed, the Palestinian Ministry of Health said on Tuesday. At least 20 humanitarian workers from the UN, the Red Cross and the Red Crescent have been killed in Gaza, the UN said.

Meanwhile, health services within Gaza are on the brink and food and water supplies are running low. Twenty out of 23 hospitals were offering partial services because fuel reserves are “almost totally depleted,” the UN Relief and Works Agency (UNRWA) warned on Tuesday.

UN agencies have warned that shops are less than a week away from running out of available food stocks and that that Gaza’s last seawater desalination plant had shut down, bringing the risk of further deaths, dehydration and waterborne diseases.

Hospitals have been receiving dozens of bodies from different areas of south Gaza, the director of Gaza hospitals, Dr. Mohammad Zaqout, told CNN. The toll includes dozens of victims from air strikes in Rafah.

The Palestinian Interior Ministry said Israeli airstrikes had killed at least 49 people in strikes on the southern Gaza cities of Rafah and Khan Younis.

IDF spokesperson Lt. Col. Jonathan Conricus told CNN he was “not aware of any strikes specifically in those areas but they could have happened.”

Closed crossing

Urgent calls for help are growing on both sides of the crossing as aid amasses on the Egyptian side of the border.

Blinken on Tuesday said the the United States and Israel “have agreed to develop a plan that will enable humanitarian aid from donor nations and multilateral organizations to reach civilians in Gaza.”

But on the Egyptian side of the Rafah crossing, UN teams wait for the the green light to enter Gaza and open a humanitarian corridor.

WHO spokesperson Margaret Harris told CNN the UN health agency had struck an agreement with Egypt’s President Abdel Fattah El-Sisi to open the Rafah crossing for aid – but Israel’s strikes rendered the facility unsafe, thereby halting the movement of crucial supplies.

On the Gaza side, large numbers of evacuees have gathered by the crossing, part of the mass displacement that has seen at least 1 million people flee their homes in the past week alone, according to UNRWA.

One family of five Palestinian-Americans, all US citizens, drove to Rafah on Monday after hearing the borders would be opened but to no avail, said Haifa Kaoud, whose husband Hesham is among the five stuck in Gaza.

The family had been visiting relatives in Gaza when the war broke out; now, their loved ones in the US are desperately trying to find ways to bring them home as they face shrinking supplies of vital medication, clean water and electricity.

A Palestinian border official told CNN on Saturday that concrete slabs had been placed at the crossing, blocking all gates; Egypt, meanwhile, claims that Israeli airstrikes on the Gaza side of the border have made roads inoperable.

Satellite images provided by Maxar Technologies show four 30-foot (9-meter) craters blocking the roadway at the border crossing closest to the Egyptian gate, along with the concrete slabs.

Delivering aid is extremely complex in Gaza, where Israeli airstrikes have repeatedly hit UN facilities in the past week.

“We need to have areas where humanitarians can move through safely, where people who are receiving humanitarian aid can receive that aid safely,” Dujarric told CNN in a press briefing Tuesday. “The last thing you would want to see is creating distribution points where people receive that aid are not safe.”

Diplomatic efforts have so far failed to ease the conflict. On Monday, the UN Security Council rejected a Russian resolution calling for a humanitarian ceasefire after it failed to get enough votes.

Several countries including the US, the United Kingdom and France voted against it because the draft did not condemn Hamas for the October 7 attack, which the Israel Defense Forces (IDF) said killed at least 1,400 people with scores taken hostage.

This includes French-Israeli woman, Mia Schem, who was shown in the first hostage video released by Hamas. Her mother, Keren Scharf Schem implored world leaders “to bring my baby back home” when speaking to reporters Tuesday.

CNN cannot independently verify where and when the video of Schem, 21, was taken and what condition she is currently in.

Fears of regional conflict

Regional leaders raised concerns of fighting between Israel and Lebanon’s powerful Iran-backed Hezbollah in the north, and Syria, as strikes at the border become a flashpoint for wider conflict.

The IDF said on Tuesday shots were fired towards several locations on the security fence between Israel and Lebanon.

At the same time, Iranian Supreme Leader, Ali Khamenei, warned if the “atrocities” against Gaza persist, “Muslims and resistance forces could lose patience,” and no-one would be able to prevent their actions.

After Hamas’ incursion on October 7, Palestinian militants fired shots from Lebanon that were intercepted by Israel, leading to a deadly exchange of fire.

On Friday evening local time an Israeli strike killed Reuters journalist Issam Abdallah who was also from south Lebanon. The assault wounded at least six other reporters.

CNN video analysis found that the journalists were wearing vest jackets clearly marked as press.

And on Tuesday, Israeli strikes killed at least four people in Alma al-Shaab, in southern Lebanon, the Lebanese Red Cross said.

Two Hezbollah fighters were killed in confrontations on Tuesday, the militant group said. It is unclear whether they are part of the death toll reported by the Red Cross.