Within hours after a blast was said to have killed hundreds at a Gaza hospital, protesters hurled stones at Palestinian security forces in the occupied West Bank and at riot police in neighbouring Jordan, venting fury at their leaders for failing to stop the carnage.

A summit planned in Jordan on Wednesday between US President Joe Biden, Jordan’s King Abdullah II, Egyptian President Abdel Fattah el-Sissi and Palestinian President Mahmoud Abbas was cancelled after Abbas withdrew in protest.

US Secretary of State Antony Blinken had spent much of the past week meeting with Arab leaders to try to ease tensions, but those efforts are now in doubt following the hospital blast. The raw nerve of decades of Palestinian suffering, left exposed by US-brokered normalisation agreements between Israel and Arab states, is throbbing once again, threatening broader unrest.

“This war, which has entered a dangerous phase, will plunge the region into an unspeakable disaster,” warned Abdullah, who is among the closest Western allies in the Mideast.

There were conflicting claims of who was responsible for the hospital blast. Officials in Gaza quickly blamed an Israeli airstrike. Israel denied it was involved and released a flurry of video, audio and other information that it said showed the blast was 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. Biden, speaking in Tel Aviv, said the blast appeared to have been caused “by the other team,” not Israel.

But there was no doubt among the Arab protesters who gathered in several countries on Tuesday to condemn what they saw as an Israeli atrocity. In the Israeli-occupied West Bank, which has been under lockdown since a bloody October 7 rampage by Hamas militants ignited the war, protesters clashed with Palestinian security forces and called for the overthrow of Abbas.

Israel and the West have long viewed Abbas as a partner in reducing tensions, but his Palestinian Authority is widely seen by Palestinians as a corrupt and autocratic accomplice to Israel’s military occupation of the West Bank.

Jordan, long considered a bastion of stability in the region, has seen mass protests in recent days. Late Tuesday, pro-Palestinian protesters tried to storm the Israeli Embassy.

“They are all normalizing Arab rulers, none of them are free, the free ones are all dead!” one protester shouted. “Arab countries are unable to do anything!”

Egypt was the first Arab country to make peace with Israel, in the late 1970s. Jordan followed in 1994. Thousands of students rallied at Egyptian universities on Wednesday to condemn Israeli strikes on Gaza. Protesters in Cairo, Alexandria and other cities chanted “Death to Israel” and “With our souls, with our blood, we sacrifice for you, Al-Aqsa,” referring to a contested Jerusalem holy site. A smaller protest was held near the US Embassy in Cairo on Tuesday.

Such protests are rare in Egypt, where authorities have clamped down on dissent for over a decade. But fears that Israel could push Gaza’s 2.3 million residents into Egypt’s Sinai Peninsula, and soaring consumer prices due to runaway inflation, could prove a volatile mix in the country, where a popular uprising toppled a US-backed autocrat in 2011.

Protests also erupted in Lebanon, where Hezbollah has traded fire with Israeli forces at the border, threatening to enter the war with its massive arsenal of rockets. Hundreds of protesters clashed with Lebanese security forces on Wednesday near the US Embassy in Beirut, where riot police lobbed dozens of teargas cannisters and fired water cannons to disperse demonstrators.

Protests have also been held in Morocco and Bahrain, two countries that forged diplomatic ties with Israel three years ago as part of the Abraham Accords.

“The Arab street has a voice. That voice may have been ignored in the past by governments in the region and the West … but they cannot do this anymore,” said Badr al-Saif, a history professor at Kuwait University. “People are on fire.”

As recently as a couple of weeks ago, the regional outlook seemed far different. In his address to the UN General Assembly last month, Israeli Prime Minister Benjamin Netanyahu boasted that the Abraham Accords, in which four Arab states normalised relations with Israel in 2020, were a “pivot of history” that “heralded the dawn of a new age of peace.”

He said Israel was “at the cusp of an even more dramatic breakthrough” – a historic agreement with Saudi Arabia that the Biden administration had been focused on in recent months.

The Abraham Accords, with the United Arab Emirates, Bahrain, Morocco and Sudan, were reached with autocratic leaders willing to set aside the Palestinian issue in order to secure their own benefits from the US. The UAE hoped for advanced fighter jets. Morocco won US support for its claim to Western Sahara, and Sudan’s ruling military junta got longstanding US sanctions lifted.

Saudi Arabia had asked for a US defence pact and aid in establishing a civilian nuclear programme, as well as a substantial concession to the Palestinians that the Saudis have yet to publicly spell out.

Shimrit Meir, who served as a diplomatic adviser to former Israeli Prime Minister Naftali Bennett, said “time will tell” what impact the war will have on normalization efforts.

“In the short term, they will suffer, especially the hope for a breakthrough” with Saudi Arabia, she said. “In the longer run, Israel’s appeal and value to these countries comes from its military strength. Therefore, the need for it to restore its deterrence is above any other considerations.”

Despite all the high-level diplomacy, ordinary Arabs and Muslims still express strong solidarity with the Palestinian cause. During last year’s World Cup soccer tournament, for example, Palestinian flags were waved in abundance even though the national team did not compete. The recent devastation in Gaza has stirred those sentiments again.

“No Arab government is able to extend its hand to Israel amid its aggression on the Palestinians,” said Ammar Ali Hassan, an Egyptian political scientist. “The Arab peoples won’t accept such a move. Even the rulers wouldn’t benefit from such ties at this time.”

• An AP report