Israel-Gaza updates: More hostages released, including 4-year-old American girl

Alma Avraham, an 84-year-old Israeli hostage released by Hamas Sunday, was taken to Soroka Medical Center in Beersheba in "serious condition," IDF spokesman Daniel Hagari said.

"Alma, who was returned to us in serious condition, was immediately evacuated by helicopter to the hospital. She was evacuated by IDF troops while still inside Gaza,” he said during a press conference.

Due to "medical reasons" and to ensure the safety of the hostages, 13 of them were escorted out of Gaza by special forces near the community of Be'eri, "in full coordination with Egyptian security authorities," Hagari added.

In a short statement, Soroka said Avraham is in "poor physical condition and severe clinical condition."

The IDF and General Security Service killed five senior Hamas officials in Gaza, IDF spokesman Daniel Hagari said Sunday, adding they were "key figures and key partners" in the Oct. 7 attack.

Hagari also said the war will not end until all the hostages are returned.

"This is the ethical and moral duty of every IDF soldier and the bodies of the defense establishment," he said.

Israeli Prime Minister Benjamin Netanyahu toured the Gaza Strip on Sunday and vowed the return of all of the hostages taken by the Hamas terror group, according to the prime minister's office.

Netanyahu spent time with Israeli commanders and fighters and visited one of the Hamas tunnels uncovered by Israeli forces, the prime minister's office said in a statement.

"We are here in Gaza with our heroic fighters," Netanyahu said in a video released by his office showing him wearing a helmet and flak jacket, and surrounded by Israeli soldiers. "We make every effort to return our abductees, and eventually we will return them all. We have three goals for this war: eliminate Hamas, return all our abductees, and ensure that Gaza does not become a threat to the State of Israel again."

Netanyahu added, "We continue until the end -- until victory. Nothing will stop us, and we are convinced that we have the power, the strength, the will and the determination to achieve all the war's goals, and we will."

-ABC News' Bruno Nota and Jordana Miller

President Joe Biden praised the release of hostages Sunday from the Gaza Strip and said he hopes the four-day cease-fire will be extended.

"Look, you know the deal calls for every 10 hostages released, we extend another day. So, I'm hopeful this is not the end, it's going to continue. But we don't know. But I get a sense that all the players in the region, even the neighbors who haven't been directly involved [up] to now, are looking for a way to end this so the hostages are all released and Hamas is completely, how can I say it, no longer in control of any portion of Gaza," Biden said at a press conference.

"I'd like to see the pause go on as long as prisoners keep coming out," he added.

Biden said there are probably other militant groups that have hostages in the Gaza Strip, and that the condition of the other Americans being held in Gaza is unclear.

The president's remarks come as 4-year-old Abigail Idan was among the hostages released Sunday.

Idan's parents were killed in front of her during the October attack in southern Israel, U.S. officials have said.

"She's been through a terrible trauma," Biden said. "What she endured is unthinkable."

Israel and Hamas are currently on the third day of a four-day pause in fighting during which Israel plans to release 150 Palestinians and Hamas will release 50 of the over 200 people it is thought to have taken hostage on Oct. 7.