The cease-fires in Lebanon and Gaza appeared increasingly fragile on Sunday after Israeli forces killed scores of people in southern Lebanon, Lebanese officials said, while in Gaza, Israel prevented Palestinians from moving back to their homes, saying Hamas had violated the terms of the truce.
In Lebanon, negotiators had hoped that the cease-fire, which was signed in November, would become permanent, securing a measure of calm in a turbulent region. Thousands of Lebanese displaced by the war have poured onto roads leading south, heading back to their homes.
But as a deadline passed on Sunday for the withdrawal of Israeli troops and the forces of the militant group Hezbollah from southern Lebanon, a very different scenario was taking shape. Lebanon’s Health Ministry said Israeli forces killed at least 22 people and injured 120 in southern Lebanon, making Sunday the deadliest day in the country since the war ended in November.
The Israeli military said in a statement late on Sunday that it had fired “warning shots in order to eliminate threats” — a formulation that suggested the shots may have been more than just warnings. It said that there had been “dozens of rioters” in the area. The military also said its soldiers had spotted a “a vehicle with Hezbollah flags” and that its forces had “operated in order to remove the threat.”
In recent days, Israeli officials have expressed concerns that Hezbollah remains active in southern Lebanon and it has doubts about the Lebanese Army’s ability to rein in the group.
Those claims could not be independently verified. The five-member committee overseeing the implementation of the cease-fire has not publicly released any information regarding Hezbollah’s compliance with the terms of the truce.
United Nations peacekeeping forces in Lebanon, known as UNIFIL, warned in a statement on Sunday that it was “imperative to avoid further deterioration of the situation.” It called on the Israeli military to avoid firing at civilians, and for Lebanese to adhere to the directives of the Lebanon’s military.
“Further violence risks undermining the fragile security situation,” the statement said.
In its statement late on Sunday, the Israeli military said it was “determined to continue to operate in accordance with the understanding between Israel and Lebanon, despite Hezbollah’s attempts to return to southern Lebanon.”
Tens of thousands of Israelis who were evacuated from their homes in northern Israel 15 months ago have been reluctant to return, fearing cross-border attacks from Hezbollah.
In the Gaza Strip on Sunday, civilians displaced by war were likewise stymied from returning to their homes. Israeli troops prevented them from doing so after Israeli officials accused Hamas of violating the terms of the cease-fire agreement that went into effect a week ago.
Officials on both sides said they were in contact with mediators to try to resolve the crisis, one of the most significant between the parties since the cease-fire brought at least a temporary halt in fighting after 15 months of devastating war.
Under the terms of the initial phase of the Gaza cease-fire agreed to this month, Israel had been expected to withdraw some of its forces and allow hundreds of thousands of uprooted Gazans to head north after a second hostage and prisoner exchange on Saturday.
The Israeli government said Hamas had violated the deal by not adhering to the agreed order of hostage releases and by failing to provide Israel with information about the status of the captives still in Gaza who were seized when the militants attacked Israel on Oct. 7, 2023.
Israeli officials said that under the agreement, one of the hostages, Arbel Yehud, an Israeli civilian, was supposed to be among the women released on Saturday as part of the exchange for Palestinians being held in Israeli prisons. Hamas freed four female Israeli soldiers and Israel released 200 Palestinian prisoners — but the whereabouts of Ms. Yehud were unclear.
Hussein al-Batsh, an official of Palestinian Islamic Jihad, a smaller armed organization and sometime rival of Hamas in Gaza, told The New York Times on Sunday that Ms. Yehud was in the custody of the Quds Brigades, the group’s military wing. He said that Ms. Yehud was not released on Saturday for “technical reasons.”
Mr. al-Batsh said that senior Islamic Jihad leaders were involved in the discussions with the mediators. A spokesman for the group, Mohammed al-Haj Mousa, then said in a statement that Ms. Yehud would be released before next Saturday to allow displaced Gazans to return to the north as quickly as possible.
Israel denied that any agreement had been reached on Ms. Yehud’s return. An official familiar with the details said on Sunday evening that contacts with the mediators were continuing and repeated that Israel would not allow displaced Gazans to move north until the issue of Ms. Yehud’s release had been resolved.
On Sunday, images of a large crowd of displaced Palestinians waiting near the Netzarim corridor — a zone built by Israeli forces that splits Gaza in two — to return north were circulating in Palestinian media.
Wafa, the Palestinian Authority’s news agency, reported that one person had been killed and several others were wounded west of Nuseirat in central Gaza after Israeli forces fired at the crowd of people waiting to return north. The Israeli military did not immediately respond to a request for comment on the reports.
One Palestinian, Ghada al-Kurd, 37, said she had chosen to remain in central Gaza on Sunday despite longing to return to her home in the north. “I will not risk my life,” she said. “Those soldiers cannot be trusted.”
Ms. al-Kurd, who left her home and her two daughters behind in Gaza City in the early weeks of the war, was once again left wondering when she would finally get to see them. “Here we are just waiting, feeling stressed and anxious,” she said. “They are playing with our fate,” she added.
Similar sentiments were expressed among the thousands of Lebanese who were attempting to return home to towns and villages along the Israeli border, despite warnings by the Lebanese and Israeli militaries that it was not yet safe to do so.
On Sunday afternoon, hundreds of people waited anxiously outside Meiss al-Jabal, a village along Lebanon’s southern border.
Ibrahim Hamoud, 41, said he had recently seen a video sent by a friend in the Lebanese Army of his house inside the village: The structure was standing, offering him a measure of relief, though the video also showed an Israeli tank stationed just outside his front door, he said.
“I’ve been away from my village, from my house, for more than a year,” Mr. Hamoud said in a phone interview. “I never thought I’d be back.”
The crisis poses a critical test for Lebanon’s new leaders. President Joseph Aoun and Prime Minister-designate Nawaf Salam, as they seek to wrest back some political control from Hezbollah and build a functioning state.
Experts warn that any prolonged Israeli occupation of southern Lebanon could breathe new life into Hezbollah, a group that was founded to liberate Lebanon from Israeli occupation and that has portrayed itself as the only force capable of protecting Lebanon’s borders.
“As long as Israel is occupying Lebanon, it’s reviving the narrative of Hezbollah,” said Sami Nader, the director of the Institute of Political Science at Saint Joseph University of Beirut.
For those who managed to enter their villages in southern Lebanon, the scale of destruction was overwhelming. Entire neighborhoods were reduced to rubble in the Israeli invasion that began on Oct. 1, 2024, which was aimed at crippling Hezbollah. The militant group began opening fire on Israel a day after the Hamas attack that set off the war in Gaza.
In the southern town of Aita al-Shaab, much of which now lies in ruin, residents walked through rubble-strewn streets and by flattened buildings. Among them was Mohamed Srour, the town’s mayor, who had been displaced more than a year ago after the strikes between Hezbollah and Israel began.
He said that Israeli soldiers had not yet fully withdrawn from the town and that they were firing sporadically at civilians. The claims could not be independently verified. Still, Mr. Srour remained resolute.
“Today, Aita is celebrating the long-awaited return,” he said. “The houses are destroyed and the livelihood is gone, but our will to live is stronger. We will build again.”
Reporting was contributed by Hiba Yazbek, Iyad Abuheweila, Johnatan Reiss, Gabby Sobelman, Myra Noveck, Hwaida Saad and Dayana Iwaza.
