A spokesman for the Israeli Defense Forces, Rear Admiral Daniel Hagari, told press outlets in Israel Monday night that its forces have discovered concrete evidence that Hamas used a children’s hospital in Gaza as a base of operations, and may have held some of the more than 230 hostages taken on October 7 at the site following the attacks.

“I just got back from Gaza, where I joined an operation inside the Rantisi Children’s Hospital,” Mr. Hagari said. “I went to the hospital with a video camera and personally documented more concrete evidence. The concrete evidence proves that Hamas uses hospitals as an instrument of war.”

In a basement of the hospital, he said, the IDF forces discovered suicide bomb vests, assault rifles, explosive, RPGs, and other weapons along with computers and cash. Al-Rantisi, the last pediatric hospital in north Gaza, closed late last week following repeated warnings from the Israel Defense Forces to evacuate. The patients were taken to other hospitals at Gaza as well as facilities in Egypt and Jordan.

In a six-minute video screened for journalists in Israel, Mr. Hagari said the troops discovered evidence that Hamas fighters returning to Gaza with hostages took refuge at the hospital in the immediate aftermath of the assault.

Among the evidence was a bullet-ridden motorcycle of the kind used to kidnap the Israelis, as well as other items left behind by the captors such as baby bottles, ropes used to bind the hostages, and a makeshift toilet. A separate room, with curtains covering solid cinderblock blocks and couches lining each wall, as well as what appears to be a guard-duty roster starting on October 7, was also depicted in the video.

Hamas “runs its terror machine under hospitals in Gaza,” Mr. Hagari said. The group, he added, “uses this children’s hospital, Rantisi, to hide.”

CNN, citing anonymous intelligence officials, reported Monday that American authorities are aware that Hamas uses one of the region’s other main hospitals, the Shifa hospital, as a base of operations, and regularly steals fuel intended for the facilities for its own purposes.

The Shifa hospital has been the source of considerable international tension as Israeli forces surrounded what it said is one of Hamas’ main military strongholds in Gaza. Several patients at the foundering facility have died in the last few days, including babies. Hamas has denied that it uses the hospital for military purposes, but the American intelligence assessments — as well as repeated claims from Israeli sources — would seem to negate those denials.

President Biden on Monday said the Shifa hospital, Gaza’s largest, must be protected. “It is my hope and expectation that there will be less intrusive action,” Mr. Biden told reporters in the Oval Office.