The complex raid deep into a built-up refugee camp in central Gaza to rescue four held hostage by Hamas on Saturday was the largest rescue operation since Hamas and other militants stormed across the border and attacked Israel, triggering the ongoing war.

Scores of hostages are believed to be held in densely populated areas or inside Hamas’ labyrinth of tunnels, making such operations extremely complex and risky.

The Israeli raid in Nuseirat camp, which dates back to the 1948 Arab-Israeli war, on Saturday led to the rescue of 26-year-old Noa Argamani, 22-year-old Almong Meir Jan, 27-year-old Andrey Kozlov and 41-year-old Shlomi Ziv, who were all kidnapped from the Nova music festival on Oct. 7.

According to the Hamas-run Gaza’s Health Ministry, at least 274 Palestinians were killed and hundreds more were wounded in the raid. The Israeli military said its forces came under heavy fire during the complex daytime operation and that “under 100” Palestinians were killed, though it was not clear how many of them were militants or civilians.

A timeline of the raid

Rear Adm. Daniel Hagari, a spokesperson for the Israel Defense Forces, told reporters on Saturday that the military has been planning the operation for several weeks, building precise models of the apartment buildings to repeatedly train.

The hostages, he said, were being held in two apartments about 200 meters (219 yards) away from each other.  They were targeted simultaneously in broad daylight because there was a “huge risk they’d kill hostages in the other one,” Hagari said.

According to Hagari, the operation in the building where they found Argamani went smoothly, while in the second building with the three male hostages, they were met with crossfire from the guards – including from gunmen firing rocket-propelled grenades from within the neighborhood. He said the military responded with heavy force, including from aircraft, to extract the rescuers and the freed hostages.

An Israeli police special forces officer was critically injured and later died in this hospital. 

Dr. Itai Pessach, a physician at Sheba Hospital where the freed captives were being treated, said none had serious physical injuries but that it would likely be days before they could be discharged.

“A lot of them have lost friends and family. Things happened in these eight months that they weren’t here. So (medical staff) have been assisting them in rebuilding the infrastructure of their life,” he told reporters.

Who are the hostages

Argamani, Meir Jan, Kozlov, and Ziv were all kidnapped at the Nova music festival. They were recovered after the IDF announced it was striking “terrorist infrastructure” in central Gaza.

Argamani has emerged as an icon of the agonizing hostage crisis that is still far from over. She appeared in a series of videos that captured the painful trajectory of their plight.

Meir Jan, from a small town near Tel Aviv, had finished his army service three months before the attack at the music festival, according to the Times of Israel. A forum set up by families of the hostages said he was supposed to start a job at a tech company the day after the attack.

Kozlov was working as a security guard at the festival. He had immigrated from Russia to Israel alone a year and a half earlier, and his mother came to the country after Oct. 7, Israeli media reported.

Ziv is from a farming community in northern Israel and was working as an usher and had gone to the music festival with two friends who were both killed, the Times of Israel reported.

U.S. provided intelligence support

The United States, one of Israel’s largest allies, provided support to the Israeli forces, two U.S. officials confirmed to CBS News on Saturday. The U.S. military did not participate in the operation, a U.S. official said.

The U.S. role came mainly in the form of intelligence support, two U.S. officials confirmed to CBS News, but they declined to share sensitive details regarding the operation. 

Video circulating online Saturday showed an IDF helicopter taking off from the beach with the temporary floating pier built by the U.S. in the backdrop. Two U.S. officials told CBS News that the U.S. pier was not used in the IDF operation. It is offshore to assist delivery of humanitarian aid. A U.S. official explained that the helicopter landed south of the facility on a beach but not within the cordoned area of the pier.

“The pier facility was not used in the operation to rescue hostages today in Gaza. An area south of the facility was used to safely return the hostages to Israel,” a U.S. official said. “Any such claim to the contrary is false. The temporary pier on the coast of Gaza was put in place for one purpose only, to help get more urgently needed lifesaving assistance into Gaza.”

Hagari, the IDF spokesperson, also said the rumor that Israeli forces came from the temporary pier was “completely false.”

“We know it’s a true ally that assists us against Hamas, against terrorists and it happens around the clock,” he said about U.S. support during the operation.

Scenes of horror at Gaza hospital

In Gaza, medics described to the Associated Press scenes of chaos after Saturday’s raid as wounded people overwhelmed hospitals that were already struggling to treat the wounded from days of heavy Israeli strikes in the area.

“We had the gamut of war wounds, trauma wounds, from amputations to eviscerations to trauma, to TBIs (traumatic brain injuries), fractures, and obviously, big burns,” Karin Huster of Doctors Without Borders, an international charity working in Al-Aqsa Martyrs Hospital, told the AP.

“Kids completely grey or white from the shock, burnt, screaming for their parents. Many of them are not screaming because they are in shock.”

The killing of so many Palestinians, including women and children, in a raid showed the heavy cost of such operations on top of the already soaring toll of the 8-month-long war.

Hostages still missing

Hamas abducted 250 hostages during its Oct. 7 attack. About half were released in a weeklong cease-fire in November. About 120 hostages remain, with 43 presumed dead. Survivors include about 15 women, two children under 5 and two men in their 80s.

Saturday’s operation brought the total number of rescued hostages to seven, including one who was freed shortly after the October attack. Israeli troops have recovered the bodies of at least 16 others, according to the government.

World Food Programme worker injured

The United Nations’ World Food Programme exeuctive director Cindy McCain told “Face the Nation” on Sunday morning that one of their workers was among those injured in the raid. 

Haley Ott, Margaret Brennan, David Martin, Clarie Day, Olivia Gazis and Ed O’Keefe contributed to this report.