Israel-Gaza updates: Gantz rejects Netanyahu's request, resigns

After meeting with rescued hostages and their families, Israeli Prime Minister Benjamin Netanyahu called the rescue operation "remarkable" and told reporters they will do "whatever it takes" to get the hostages back.

"We're committed to getting the release of all the hostages, and we expect Hamas to release them all — but if they don't, we'll do whatever it takes to get them all back home. Hamas is committing war crimes every day, including the holding of these hostage.s. Our soldiers are performing in the most valiant and moral way to end this war with a victory against these killers and against these kidnappers, and we shall prevail," Netanyahu said.

Earlier, the Israel Defense Forces said the hostages were being held in civilian populated areas, without any way to reach them but go through Gaza civilians, IDF spokesman Daniel Hagari told reporters. Three male hostages were held together in an apartment and a fourth female hostage was held in another apartment just over 650 feet away, Hagari said.

At least 150 Palestinians were killed in Israeli raids on Saturday, the Hamas-run Gaza Health Ministry said.

A United States official provided ABC News with more details about the rescue efforts, noting that the U.S. has been providing regular intelligence sharing and expertise on hostage recovery efforts since Oct. 7.

The official stressed there were no American boots on the ground as part of this effort.

-ABC News' Dana Savir, Bruno Nota and Molly Nagle

President Joe Biden and French President Emmanuel Macron welcomed the rescue of the hostages at a press briefing Saturday.

Biden welcomed the safe return of four hostages from Gaza, pledging that the United States will not stop working until all hostages are home.

"I want to echo President Macron’s comments welcoming the safe rescue of four hostages that were returned to their families in Israel. We won't stop working until all the hostages come home and a ceasefire is reached. That is essential to happen,” Biden said.

President Macron spoke before President Biden, also celebrating the news.

“In Gaza, we want to attain the immediate liberation of hostages and we can only welcome the liberation of four hostages by the Israeli army. We want to achieve the immediate ceasefire and open up the prospect of a political solution which is the only one that can bring about a fair and lasting peace and meet the security of concerns of both people,” Macron said.

“And that is why we are supporting the comprehensive proposal of the United States of America,” he added, calling on Israel to do more to assist humanitarian aid to Rafah, calling the situation “unacceptable.”

-ABC News’ Molly Nagle and Michelle Stoddart

At least 150 Palestinians were killed in Israeli bombing targeting Nuseirat, in central Gaza, Saturday, according the Ministry of Health.

One video verified by ABC News shows about a dozen bodies lying on the street, covered in blood and surrounded by rubble.

Others show people fleeing Nuseirat market as smoke fills the background, and people arriving at the hospital in droves, carrying wounded people and children.

Al Aqsa Martyrs Hospital says it received 55 bodies Saturday amid the Israeli raid on central Gaza, calling on people to come to donate blood, according to a spokesperson.

The hospital is overcrowded and cannot accommodate any more injured people, it said.

“We call on the international community and UN organizations to intervene to stop this brutal aggression,” the hospital said in a statement.

-ABC News’s Victoria Beaule