As information emerges about at Gaza's , both Israeli and Palestinian officials have put forward contradictory narratives on what happened and each denied responsibility.
Here is what is known so far, and answers that are needed to provide more context on the attack.
How many people were killed?
In the first hours after the blast, a Gaza civil defence chief said 300 people were killed, while health ministry sources put the figure at 500.
Wounded Palestinians wait for treatment in al-Shifa Hospital in Gaza City, central Gaza Strip, after arriving from al-Ahli Arab Hospital following an explosion there. Source: AAP, AP / Abed Khaled
What happened before the strike?
Israel previously told Palestinians in the north of Gaza, including in Gaza City, to move south for their own safety. Israel's military specifically told residents of the Zeitoun district of Gaza City to move south on Tuesday in a message issued on social media platform X.
The Kuwaiti specialist hospital in Rafah city, in the south of Gaza, said on Monday it had received two Israeli warnings to evacuate but its director said its staff would not leave.
What details do we have about the strike?
Dr Fadel Naim, head of orthopaedic surgery at the al-Ahli Arab Hospital, said he had finished one surgery and was about to start another when he heard a huge explosion. Another doctor at the hospital, Ibrahim Al-Naqa, spoke to Reuters about the scenes at the hospital in the attack's aftermath. He said the blast took place at about 6.30pm local time on Tuesday.
Live footage from the Al-Jazeera media network aired at 18:59 local time showed a bright light rising in the skies above Gaza. It flashes twice before drastically changing direction, and it then explodes.
What was the damage?
Footage and images obtained by Reuters from inside the hospital showed about two dozen destroyed vehicles on its grounds.
What do we know about the hospital?
Founded in 1882 and run by the Anglican church, al-Ahli Arab Hospital is described on its website as "a haven of peace in the middle of one of the world’s most troubled places". The hospital offered 80 beds with services such as a free program to detect breast cancer, a centre for elderly women, and a mobile clinic offering free services to surrounding towns.
It is located in the Zeitoun neighbourhood of Gaza City, in the northern region of the Gaza Strip.
How many people were in the hospital?
Although it had a limited number of beds, the hospital and have been crammed with casualties beyond their capacity since the start of Israeli air strikes launched in response to the 7 October Hamas attack on Israel.
As well as handling a surge in the number of wounded, people have also sought refuge in hospital grounds all over Gaza, believing them to be safe havens against strikes.
Naim said about 1,000 people were in al-Ahli Arab Hospital on Tuesday morning and more were rushed there later in the day after he said the Israeli army had warned residents in the Zeitoun neighbourhood to evacuate their homes.
A Palestinian girl carries blankets as she walks past the site of a deadly explosion at al-Ahli Arab Hospital in Gaza. Source: AAP / Abed Khaled/AP
What does US intelligence say about the blast?
US President Joe Biden said of the hospital blast: "Based on the information we have seen today, it appears the result of an errant rocket fired by a terrorist group in Gaza."
In Washington, the White House National Security Council echoed Biden, saying the US assessment was based on analysis of overhead imagery, intercepts and open-source information.
The strike has inflamed Arab governments and groups in the region. Protesters took to the streets in several Arab countries denouncing what they said was an Israeli strike on the hospital.
Jordan's King Abdullah blamed Israel for the blast and his country cancelled a summit it was to host in Amman on Wednesday to discuss Gaza with the US president and the Egyptian and Palestinian leaders. Egypt also blamed Israel.
In Lebanon, Iran-based Hezbollah, which fought a war with Israel in 2006, denounced what it called Israel's deadly attack and called for protests on Wednesday. The Beirut government declared a national day of mourning.
What have Gaza officials said about the blast?
The Palestinian Authority's health minister, Mai Alkaila, accused Israel of "a massacre" at al-Ahli Arab Hospital.
The health ministry spokesman, Ashraf Al-Qudra, said early on Wednesday that hundreds were killed and that rescue workers were still removing bodies from the rubble.
What has Israel said?
Israeli Prime Minister Benjamin Netanyahu said "barbaric terrorists" in Gaza had attacked the hospital, not Israel's military.
Israeli military spokesperson Rear Admiral Daniel Hagari told reporters rockets fired by the Palestinian Islamic Jihad militant group passed by the hospital at the time of the strike, which he said hit the facility's parking lot.
While briefing reporters, Hagari cast doubt on the Palestinian death count in the hospital strike and claimed there was no direct hit on the facility. He said military drone footage showed "a kind of hit in the parking lot."
The Israel Defence Forces (IDF) released a recording of what it says is an intercepted conversation between two Hamas militants saying the hospital was hit by a projectile fired by Palestinian Islamic Jihad.
This has not been verified.
What about other groups?
Islamic Jihad denied that any of its rockets were involved in the hospital blast, saying it did not have any activity in or around Gaza City at that time.
Iran-backed Islamic Jihad took part in the assault on Israel on 7 October and, like Hamas, has fired numerous salvoes of rockets into Israel.
What information is missing about the blast?
Without any group taking responsibility for the blast it cannot be determined for certain yet who is responsible.
BBC Verify said it spoke to three experts who said the explosion is not consistent with what you would expect from a typical Israeli air strike with a large munition, but also spoke to three experts who gave other responses.
Missile fragments may be able to give further clues, but these have not yet been identified.
The IDF say that the absence of a large crater, or blast damage to adjacent buildings, proves that the explosion was not caused by its weapons.
More evidence about the damage left at the blast site and any craters could provide more clarity on this.
Verified figures on the number of people killed have not been published yet.
