Israel-Gaza updates: Israel says ground operation underway in southern Gaza

Two Palestinian children were allegedly gunned down by Israeli soldiers operating in the militant stronghold of Jenin in the Israeli-occupied West Bank on Wednesday, according to Palestinian health officials.

The Palestinian Authority, the Fatah-led governing body that oversees parts of the West Bank, identified the two victims as an 8-year-old boy and a 15-year-old boy who it said "were killed by occupation bullets in Jenin."

The Palestine Red Crescent Society confirmed that its crews had transported the younger child from Jenin's al-Basateen neighborhood before he was pronounced dead.

Surveillance footage reviewed by ABC News purportedly shows the moment both boys were shot, but the perpetrators were out of sight.

ABC News has reached out to the Israel Defense Forces for comment.

The alleged incidents occurred as the Israeli military carried out hourslong raids on the Jenin refugee camp.

Deadly violence has surged in the West Bank since Hamas, the rival Palestinian faction that governs the Gaza Strip, carried out an unprecedented attack on neighboring Israel on Oct. 7, prompting Israeli forces to retaliate.

-ABC News' Nasser Atta and Morgan Winsor

Approximately 1.3 million people are currently living in shelters in the war-torn Gaza Strip, according to head of the World Health Organization, who warned Wednesday that "a sustained ceasefire" between Israel and Hamas is "a matter of life or death for civilians" in Gaza.

WHO Director-General Tedros Adhanom Ghebreyesus said "overcrowding and lack of food, water, sanitation and basic hygiene, waste management and access to medication are resulting in a high number of cases of" various contagious diseases, including 111,000 cases of acute respiratory infections, 12,000 cases of scabies, 11,000 cases of lice, 75,000 cases of diarrhoea, 24,00 cases of skin rash, 2,500 cases of impetigo, 2,500 cases of chickenpox and 1,100 cases of jaundice.

"On top of all this: heightened risk of disease outbreaks," Tedros wrote in a post on X, the social media platform formerly known as Twitter.

"Given the living conditions and lack of health care, more people could die from disease than bombings," he added. "We need a sustained ceasefire. NOW. It's a matter of life or death for civilians."

Gaza, a 140-square-mile territory governed by the Palestinian militant group Hamas, is home to more than 2 million people.

-ABC News' Morgan Winsor

The Israeli Prime Minister's Office said Wednesday that 161 hostages are still being held in the Gaza Strip.

Of the 161 remaining hostages, 126 are male and 35 are female. Among them are 146 Israelis and 15 foreigners, including Americans. Ten of them are age 75 and older, four are 18 or 19, and four are under the age of 18, according to the Israeli Prime Minister's Office.

So far, 86 hostages -- 66 Israelis and 20 foreigners -- have been freed since last Friday in exchange for the release of dozens of Palestinians from Israeli prisons as part of a cease-fire agreement between Gaza's militant rulers, Hamas, and Israel. Another prisoner swap is expected to take place Wednesday.

-ABC News' Jordana Miller, Joe Simonetti and Morgan Winsor

The United States' Special Presidential Envoy for Hostage Affairs Roger Carstens, often referred to as the country's top hostage negotiator, will travel to Israel on Wednesday, according to a senior official in the U.S. Department of State.

The official said that Carstens "will support Secretary Blinken's visit to the region, meet with Israeli government counterparts and visit the families of Americans held hostage in Gaza."

U.S. Secretary of State Antony Blinken is expected to arrive in Israel on Wednesday night.

It will be Carstens' first known trip to Israel since Oct. 7, when Palestinian militant group Hamas carried out an unprecedented attack on southern Israel and took hundreds of people hostage back to the neighboring Gaza Strip. Carsten's deputy, Steven Gillen, visited Israel shortly after the war broke out and has spent a substantial amount time in the region during the weeks that followed, largely coordinating with Israeli officials on efforts to free the hostages.

Earlier this month, Carstens met with family members of some of the hostages in Washington, D.C.

-ABC News' Shannon Crawford and Morgan Winsor