Turkey's presidential communications office has, without evidence, branded Israel's claims that a Palestinian group’s failed rocket launch caused the deadly Gaza hospital blast as “#FakeNews”.

The accusation against Israel was made on social media platform X as fury spread in the Middle East and around the world over the claimed deaths in an explosion of at least 471 people and the injuring of 314 others at Al-Ahli al-Arabi hospital on Tuesday October 17 [Editor's note: Israel on October 19 claimed the number of those who lost their lives was actually in the dozens, rather than in the hundreds as claimed by Palestinian officials]. It was also made as many Turks took to the streets to express their anger over the blast blamed by Palestinian officials on an Israeli air strike. Turkish protesters clashed with police overnight in several demonstrations. Further protest rallies were expected on Wednesday.

Israel's National Security Council (NSC) issued a warning against travel to Turkey, relaying fears that Israelis would be targeted by those angry at the war centred on Gaza between Israel and Palestinian militant group Hamas. It also urged Israeli citizens in Turkey to leave the country as soon as possible.

Early on Wednesday, US President Joe Biden flew into Israel to address the Gaza crisis inflamed by the hospital tragedy. “Based on what I have seen, it was done by the other team, not you,” Biden told Israeli Prime Minister Benjamin Netanyahu in Tel Aviv. He made the comment after assessing evidence said to indicate that the hospital car park was hit by a failed rocket attack on Israel launched from a cemetery near the hospital by the Palestine Islamic Jihad (PiJ) group.

Biden also remarked that "there's a lot of people out there who are not sure [about who conducted the attack], so we've got to overcome a lot of things".

Asked by journalists how he could be sure Israel did not strike the hospital, Biden referred to the “data I was shown by my defence department”. In comments posted on X, Biden said he had asked “tough questions of my counterpart [Netanyahu]”.

Hamas accused Biden of being “blindly biased”, Reuters reported.

Israel released what it said was an intercepted conversation between Palestinian militants that it claimed showed the Palestinians knew that the explosion was caused by a misfired rocket launched by PiJ.

Israel Defence Forces (IDF) spokesman Daniel Hagari told reporters at a briefing that if an Israeli missile had hit the hospital compound there would have been bigger "craters and structural damage". The PiJ, he insisted, were to blame. Hagari added that the IDF's aerial footage analysis showed "with absolute certainty" that the blast was caused by a "misfired" PiJ rocket fired from the cemetery near the hospital.

Hamas, claimed Hagari, "decided to launch a global media campaign to hide what really happened".

BBC Verify has assessed what the evidence available so far can tell experts about the cause of the explosion.

Ahead of the Biden visit, Turkish President Recep Tayyip Erdogan, offering no evidence, called the explosion "the latest example of Israeli attacks devoid of the most basic human values".

As bne IntelliNews reported on October 11, Erdogan has been accused of warning Israel not to commit war crimes such as killing children and destroying civilian infrastructure such as power grids, potable water stations and schools, while committing those very crimes himself by ordering brutal attacks on Syrian-Kurdish occupied areas of northeastern Syria.

Turks marched with Palestinian flags and chanted slogans denouncing Israel in at least a dozen Turkish cities. An angry rally formed outside the Israeli embassy in the capital Ankara. Police, meanwhile, used pepper spray and water cannon to disperse thousands of protesters who attempted to enter the compound of Israel's consulate in Istanbul. Five people were detained.

Israeli airlines said they were arranging flights from Istanbul on Wednesday for Israelis who wanted to depart Turkey.

Analysts said the Gaza hospital blast could have dire consequences for ties between Israel and Turkey.

"Erdogan may even decide to abandon the rapprochement with Israel, which was initiated in 2022 after more than 10 years of fraught ties between the two countries... A deterioration in relations between Turkey and Israel would also likely impact Turkey-US ties, creating further stress between the two Nato allies at a volatile time," said Wolfango Piccoli at risk advisory firm Teneo. "Ankara is now likely to assume a much harder anti-Israel stance...," he added.

Ashraf Al Qudra, spokesman for the Ministry of Health in Gaza, on Wednesday reiterated the accusation that Israel was to blame for the blast at the hospital site. He added that since Israel began its air strikes on Gaza, 3,478 people have been killed, with 12,065 injured.

Osama Hamdan, a Hamas official, told a news conference in Lebanon that the US, as well as all Western countries that support Israel, "hold full responsibility for the war against civilians in Gaza". The conflict broke out following Hamas’ surprise cross-border attacks into Israel that resulted in the massacre of at least 1,300 people.

Arab governments cancelled a planned summit with Biden in Jordan.

As well as the Turkey protests, there were angry protests in the Israeli-occupied West Bank, Lebanon, Jordan, Libya, Yemen, Tunisia, Morocco and Iran.

Turkey said it remained in talks with Hamas to secure the release of nearly 200 hostages held in Gaza by the group.