An Israeli airstrike killed at least 90 Palestinians in a designated humanitarian zone in Gaza on Saturday, according to the enclave’s health ministry. The strike targeted Hamas military chief Mohammed Deif, Israeli officials said.

Israeli Prime Minister Benjamin Netanyahu stated that it was unclear if Deif and another Hamas commander had been killed. He promised continued efforts to target Hamas leadership, asserting that increased military pressure would improve chances of a hostage deal. “Either way, we will get to the whole of the leadership of Hamas,” Netanyahu said at a news conference.

Hamas denied Deif’s death, with a senior official telling Al Jazeera TV that Israeli claims were false and aimed at justifying the attack. The airstrike is the deadliest Israeli attack in Gaza in weeks.

UN Secretary-General Antonio Guterres expressed shock and sadness over the civilian deaths, underscoring that “nowhere is safe in Gaza.” He emphasized the need to uphold international humanitarian law.

The Israeli military said the strike against Deif also targeted Rafa Salama, the commander of Hamas’ Khan Younis Brigade, describing them as masterminds of the October 7 attack on southern Israel. Deif, on Israel’s most wanted list for decades, has survived seven assassination attempts.

The Gaza health ministry reported that at least 91 Palestinians were killed and 300 injured in the strike. Al-Mawasi, a designated humanitarian area, had been urged by the Israeli army as a safe zone for Palestinians.

Footage from the scene showed ambulances amidst clouds of smoke and dust, with displaced people fleeing in panic. The Israeli military claimed the strike hit an operational compound run by Hamas and not a tent complex.

U.S. Defense Secretary Lloyd Austin spoke with Israeli Defence Minister Yoav Gallant about the Gaza operations, stressing the need to minimize civilian harm. The EU’s Foreign Affairs representative, Josep Borrell Fontelles, called for an independent probe into potential violations of international law.

Nasser Hospital, overwhelmed by the number of wounded, reported severe shortages of medical supplies. Hospital director Atef al-Hout said, “The hospital is full of patients, it’s full of wounded, we can’t find beds for people.”

Ceasefire talks in Doha and Cairo were halted after three days, with Egyptian sources citing internal discord among Israeli mediators. Hamas leader Ismail Haniyeh called for an end to the “massacres against our people.”

Netanyahu affirmed his commitment to the framework presented by U.S. President Joe Biden. The White House stated it was seeking more information about the civilian casualties reported in the attack.

Separately, at least 20 Palestinians were killed in an Israeli attack on a prayer hall at a Gaza camp for displaced people in west Gaza City, according to health and civil emergency officials.

Critics accuse Israel of committing genocide against Palestinians, a charge Israel denies, characterizing its actions as self-defense. Hamas-led militants killed 1,200 people and took more than 250 hostages in an October 7 raid into southern Israel. In response, Israel’s military actions in Gaza have killed more than 38,000 Palestinians, according to medical authorities in Gaza.