Netanyahu vowed to inflict a high price on the Yemeni group.
As the Israel-Hamas war continues, the latest round of cease-fire discussions appears to have reached an impasse.
Meanwhile, after six hostages were found dead in Gaza, protests erupted in Israel. Protesters have lashed out at Prime Minister Benjamin Netanyahu and demanded the government bring the hostages home.
The first round of the polio vaccination campaign in Gaza was completed Thursday.
Hundreds of thousands of children received dosages, successfully reaching 90% vaccination coverage, according to the United Nations Relief and Works Agency for Palestine Refugees in the Near East.
"Our next challenge will be providing the second dose, needed in the coming weeks," the UNRWA said.
In the wake of the deadly Israeli airstrikes that hit a school serving as a shelter in Gaza, United Nations Secretary-General António Guterres called for an investigation into the incident.
In a statement Thursday, Guterres said, "This horrific violence must stop."
The strikes Wednesday on the Nuseirat shelter in the Gaza Strip killed 18 people, including children, women, and six U.N. staff members, according to Guterres.
"This incident must be independently and thoroughly investigated to ensure accountability," Guterres said in his statement.
The number of U.N. staff members killed during the Israel-Hamas conflict has risen to 220, Guterres said.
"The continued lack of effective protection for civilians in Gaza is unconscionable," Guterres added. "Civilians and the infrastructure they rely on must be protected and the essential needs of civilians met."
Guterres asked for "all parties to refrain from using schools, shelters or the areas around them for military purposes."
The secretary-general reiterated his call for an "immediate cease-fire" and the "immediate and unconditional release of all hostages."
In the nearly four months the Israel Defense Forces have been in Rafah, it has not found any operational smuggling tunnels beneath the Gaza-Egypt border, multiple Israeli sources told ABC News.
The IDF found nine tunnels that ran under the Philadelphi corridor, all of which were blocked at some point on the Egyptian side, sources said. The IDF has located a total of 200 tunnels in the Rafah area.
For months, the military has been pushing back against Prime Minister Benjamin Netanyahu’s claims that Israel needs to maintain a military presence on the Philadelphi corridor because that’s where Hamas smuggles weapons into Israel via the tunnels.
This pushback has become increasingly vocal, and is echoed by the very top of the military and defense chain of command. They are quietly demanding a cease-fire deal and are calling Netanyahu’s bluff.
IDF sources said they now believe most of the smuggling was happening above ground through the Egypt-Gaza border crossing.
-ABC News' Matt Gutman
The World Health Organization said it had evacuated at least 97 patients and 155 companions from Gaza on Wednesday, taking them to the United Arab Emirates for medical treatment.
This was the largest medical evacuation from Gaza since October 2023, according to Richard Peeperkorn, WHO representative for the occupied Palestinian territory.
Patients were transported in ambulances via the Kerem Shalom crossing from Gaza to Ramon Airport in Israel for travel to Abu Dhabi.
Patients included 45 children and 52 adults with a wide range of diseases, including cancer, cardiovascular disease, congenital anomalies, blood and liver diseases, trauma and injuries.
-ABC News' Will Gretsky
