Israel-Hamas Live Updates: Latest News on the War and Gaza Aid

American intelligence officials said Tuesday they now had “high confidence” that the blast at Al-Ahli Arab Hospital in Gaza last week was the result of a Palestinian rocket that broke up mid-flight, and that no Israeli weapon was involved in the explosion.

The officials said, however, that numerous mysteries still remained about the incident. Those include how many people were killed or injured when, by the U.S. account, the warhead of a Palestinian rocket landed in the parking lot of the hospital. But they said there was little damage to the hospital itself, and no collapse of the structure.

U.S. intelligence agencies released no new imagery or other new evidence to make their case. Instead, they said their strengthened assessment came from Israeli intercepts of Palestinian armed groups and publicly available video. Those videos, the U.S. officials said, allowed them to assess that the rocket was launched from Gaza and, after a “catastrophic motor failure,” the warhead fell on the hospital’s parking lot. The officials, who spoke on the condition of anonymity to discuss sensitive information, said there was no evidence an Israeli launch could have been responsible.

A U.S. intelligence official said the analysis of the videos has focused primarily on one recorded by Al Jazeera, though there are multiple videos of projectiles in the skies and the explosion at the hospital. The U.S. intelligence analysis of the Al Jazeera video is at odds with a New York Times investigation, which found that the projectile shown in that video and others was launched from Israel and exploded well away from the hospital. A spokesman for the Office of the Director of National Intelligence said The Times and intelligence agencies had different interpretations of the video.

U.S. officials said their assessment was also based on communications intercepts provided by the Israelis and images of the explosion and aftermath. Last week, U.S. officials said their early intelligence showed that the blast was caused by an armed Palestinian group, rebutting Palestinian claims that an Israeli strike caused the explosion. U.S. spy agencies did not release detailed evidence at the time to support their assessment.

On Tuesday, U.S. intelligence officials reaffirmed their assessment that Israel was not responsible for the explosion. The evaluation reflected a higher degree of certainty by U.S. intelligence officials that Israel was not responsible for the blast.

Israel has said the explosion, which resulted in a significant number of casualties, was caused by Palestinian Islamic Jihad, a group allied with Hamas. The group said Israel’s accusations that one of its rockets malfunctioned and hit the hospital were “false and baseless.” Hamas has not provided any documentation of Israeli involvement.

The hospital blast prompted protests around the region. In an early claim, Hamas said that the hospital had been hit by an Israeli missile. President Biden, flying to Israel for a visit, said last week that preliminary evidence was that the strike had been “done by the other team,’’ but that the conclusion was preliminary.

But the initial account by Hamas took hold, especially at a time when Israel was carrying out airstrikes in advance of a potential ground attack intended to eliminate Hamas after the terror attack that the Israeli government says killed more than 1,400 people. Israel’s relentless artillery and bombing campaign in response has killed 5,700 Palestinians, according to the Hamas-run Gazan Health Ministry.

The latest American assessment is in part based on what has not been discovered. A senior intelligence official said there were no images of any Palestinians displaying an Israeli weapon from the bomb site.

U.S. officials said only light damage was sustained at the site, which is consistent with the premise of a Gaza-made rocket that broke up in flight, rather than an Israeli munition striking the hospital.

Images of a fireball at the hospital site, and pictures taken after the fact showing burned cars in the compound’s parking lot, are consistent with a malfunctioning missile, according to U.S. officials.

The American assessment also relies heavily on intercepts provided by Israeli intelligence agencies. U.S. officials said the Israelis have provided multiple recordings that American intelligence agencies say they have authenticated. All of the recordings are secondhand accounts: members of Hamas discussing their belief that the explosion was caused by an errant or malfunctioning rocket fired by Palestinian Islamic Jihad. U.S. officials did not provide recordings or transcriptions of these intercepts.

The declassified assessment provides no specific information on where U.S. intelligence officials think a rocket causing the blast was launched from inside Gaza.

But the senior official said the agencies were continuing to investigate. If the United States gets additional information that would point in a different direction, the official said, intelligence agencies will release it.

On Monday, Prime Minister Rishi Sunak of Britain said his country’s intelligence services assessed that a Palestinian rocket fired from Gaza and aimed at Israel was likely the cause of the deaths at the hospital.

“On the basis of the deep knowledge and analysis of our intelligence and weapons experts, the British government judges that the explosion was likely caused by a missile or part of one that was launched from within Gaza towards Israel,” Mr. Sunak said.

Last week, U.S. intelligence agencies said that they were working to corroborate an Israeli assessment that the explosion resulted from an errant rocket fired by Palestinian Islamic Jihad.

The number of casualties from the explosion at the hospital remains in dispute.

U.S. officials estimated last week that between 100 and 300 people were killed, but said the death toll was likely at the low end of that range. On Tuesday, U.S. officials said they only had low confidence in that assessment. The Hamas-run health ministry in Gaza said the death toll was 471, a figure revised down from their earlier assessment of 500.

U.S. officials said on Tuesday that an accurate count of the people who died at the hospital was impossible to obtain because of a lack of independent sources.

Days after Hamas accused Israel of bombing a hospital in Gaza City and killing hundreds of people, the armed Palestinian group has yet to produce or describe any evidence linking Israel to the blast, says it cannot find the munition that hit the site and has declined to provide detail to support its count of the casualties.

The Hamas-run health ministry has also declined to release further details about those 471 victims, and all traces of the munition have seemingly vanished from the site of the blast, adding to the difficulty in assessing its provenance. Raising further questions about Hamas’s claims, the impact site turned out to be the hospital parking lot, and not the hospital itself.