Israel-Gaza updates: 17 more hostages released, including 4-year-old American girl, officials say

The Israel Defense Forces and the Israel Securities Authority announced in a joint statement Monday that their troops have killed three more Hamas commanders while continuing ground operations in the Gaza Strip.

"IDF fighter jets, directed by IDF and ISA intelligence, killed three additional Hamas company commanders," the statement read in part. "In addition, IDF troops identified a terrorist cell as they entered a nearby building. As a result of the strike carried out by an IDF aircraft, the terrorists were killed and a weapons depot in which they hid was struck."

There was no immediate confirmation or comment from Hamas.

-ABC News' Dorit Long and Morgan Winsor

Israel Defense Forces troops exposed a 180-foot tunnel 32 feet deep underneath the Shifa Hospital, the IDF and Israel Securities Authority (ISA) said in a joint statement Sunday.

"A deep staircase leads to the entrance of the tunnel shaft, which consists of various defense means including a blast-proof door and a firing hole," the statement continues. "This type of door is used by the Hamas terrorist organization to block Israeli forces from entering the command centers and the underground assets belonging to Hamas. The tunnel shaft was uncovered in the area of the hospital underneath a shed alongside a vehicle containing numerous weapons including RPGs, explosives and Kalashnikov rifles.

"IDF and ISA forces are continuing to uncover the route of the tunnel," the statement adds.

The IDF said it expects to find more tunnels and underground facilities, and that the operation is ongoing and will take some time. About 300 people remain in the hospital, according to the IDF.

-ABC News' Yael Benaya

The World Health Organization confirmed earlier claims by the Palestinian Health Ministry that 31 "very sick" babies were safely transported from Al-Shifa Hospital to another hospital in southern Gaza on Sunday.

The premature infants were evacuated to the Emirates Hospital in Rafah, WHO officials said.

The babies were "clinging to life," the United Nations International Children's Emergency Fund (UNICEF) said in a statement, and their "condition was rapidly deteriorating."

The babies are expected to be transferred to another hospital in Egypt, said Dr. Ashraf al Qwadwa, a spokesperson for the Palestinian Health Ministry. He said nine premature babies have died since the start of a fuel crisis in Gaza prompted by the ongoing conflict.

Six health workers at the Al Shifa Hospital and 10 family members of staff there were also evacuated on Sunday along with the babies, according to the WHO statement, adding that further missions are planned to "urgently transport" the remaining patients and health staff out of the hospital.

-ABC News' Nasser Atta

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