Israel-Gaza updates: IDF says it exposed Hamas tunnel under Shifa Hospital

A British-owned cargo ship operated by a Japanese company was hijacked by Houthi militants near Yemen in the southern Red Sea, officials said Sunday.

The Israel Defense Forces released a statement describing the hijacking as a "very grave incident of global consequence."

"The ship departed Turkey on its way to India, staffed by civilians of various nationalities, not including Israelis," the IDF said. "It is not an Israeli ship."

Israeli Prime Minister Benjamin Netanyahu's office called the incident an "Iranian attack on an international ship," adding the vessel was "hijacked on [an] Iranian whim by the Houthi militia in Yemen."

Netanyahu's office confirmed that no Israelis were on the ship, saying the 25-person crew was of different nationalities, including Ukrainians, Bulgarians, Filipinos and Mexicans.

The Houthi militant group is expected to hold a news conference, a spokesperson for the group said.

A spokesman for Yemen's Iran-aligned Houthi military, Yahya Sarea, had said earlier Sunday the group would target all ships owned or operated by Israeli companies or carrying the Israeli flag, according to the group's Telegram channel.

-ABC News' Nasser Atta, Jordana Miller and Dana Savir

Negotiations to free the more than 200 hostages believed to be held by Hamas in Gaza have "reached a very sensitive stage" as some of the key areas of disagreement have "narrowed," a top White House official told ABC's "This Week" on Sunday.

Jon Finer, deputy national security adviser to the White House, suggested that a breakthrough in the negotiations could be imminent.

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Some ‘gaps’ have ‘narrowed’ in Israel-Hamas talks: Jon Finer

ABC News’ Martha Raddatz interviews White House Deputy National Security Adviser Jon Finer on “This Week.”

"These talks have clearly reached a very sensitive stage," Finer told "This Week" co-anchor Martha Raddatz. "We’re following this minute by minute, hour by hour, and have been over a number of weeks. And this is an incredibly high priority for all of us in this administration up to and including, certainly, the president."

Amid new reporting by The Washington Post that an agreement is on the verge of being struck for dozens of captives to be released in exchange for a pause in the fighting, Finer said progress was being made but cautioned that the work was not done.

-ABC News' Tal Axelrod

Humanitarian officials with the United Nations described the situation inside Gaza's Al-Shifa hospital as "desperate" and "a death zone" after they visited the site on Saturday.

The World Health Organization, a U.N. agency, said there was "heavy fighting" ongoing nearby. The Israeli military deconflicted the fighting during a one-hour visit to the hospital, WHO officials said.

"Signs of shelling and gunfire were evident," the WHO said in a statement. "The team saw a mass grave at the entrance of the hospital and were told more than 80 people were buried there."

The corridors and hospital grounds were "filled with medical and solid waste," WHO officials said. They described the staff as terrified and said patients "pleaded for evacuation."

Due to the conditions, the WHO are now working "urgently" to develop plans to evacuate the remaining patients and staff.

-ABC News' Guy Davies

In a sit-down interview with ABC News in Beirut on Saturday, Osama Hamdan, a senior official with Hamas in Lebanon, said the goal of the Oct. 7 attack was to show Israel and the world that the "Palestinian cause is still alive."

He said he believes that the operation has worked to that end.

"The United States start to talk about the rights of the Palestinians. All the world starts to talk about the rights of the Palestinians," he said.

Despite eyewitness accounts, news reports and video evidence, Hamdan denied that Hamas killed innocent people at a music festival in southern Israel on Oct. 7 or that they took civilian hostages from Israel. Hamdan claimed that Hamas militants only took military "prisoners," and that civilian hostages were taken by other groups. He said Hamas is willing to release hostages -- but only if Israel agrees to a cease-fire.

More than 260 bodies were recovered from the musical festival following the attack, Israeli officials said. At least 1,200 people total were killed in Israel and nearly 240 people were taken hostage in the Oct. 7 attack, Israeli officials said.

Asked if Hamas bears any responsibility for the deaths of thousands of innocent Palestinians, Hamdan said "it may take more sacrifices" but that more lives could be saved "by forcing Israel to recognize the rights of the Palestinians, to leave the occupied lands" and to let Palestinians determine their future.

-ABC News' Bruno Roeber, Ghazi Balkiz and Marcus Moore