Hamas said Saturday it was delaying the handover of a second group of hostages due to be released under a truce deal until Israel "adheres to the terms of the agreement".
The entry of humanitarian aid to the north of the Gaza Strip and the selection criteria for the liberation of prisoners were the issues in question, the Ezzedine al-Qassam Brigades said in a statement.
The group of hostages seized in the Hamas attacks on southern Israel on October 7 was due to be handed over on the second day of a four-day truce agreement.
A Hamas source had told AFP that the handover of 14 hostages to the Red Cross had begun, then said the transfer process had been halted.
An Israeli official said the hostages had not yet been handed over to the Red Cross.
"Israel has not violated the agreement," an Israeli source told AFP.
The UN peacekeeping force in Lebanon said Israeli fire hit one of its patrols in the country's south on Saturday, despite a Hamas-Israel truce largely quietening the Lebanon-Israel frontier.
"At around 12:00 pm, a UNIFIL patrol was hit by IDF (Israeli army) gunfire" in the vicinity of Aitarun, the United Nations Interim Force in Lebanon said in a statement.
"No peacekeepers were injured, but the vehicle was damaged," it said, adding that "this incident occurred during a period of relative calm" along the border between Israel and Lebanon.
UNIFIL said "This attack on peacekeepers, dedicated to reducing tensions and restoring stability in south Lebanon, is deeply troubling," adding: "We condemn this act."
Late last month, shelling lightly wounded a UN peacekeeper near the border village of Hula, just hours after UNIFIL said a shell hit its headquarters in Naqura near the Israel-Lebanon frontier. The force said it was investigating those incidents.
"We strongly remind the parties of their obligations to protect peacekeepers and avoid putting the men and women who are working to restore stability at risk," Saturday's UNIFIL statement said.
UNIFIL was set up in 1978 to monitor the withdrawal of Israeli forces after they invaded Lebanon in reprisal for a Palestinian attack.
It was bolstered after Hezbollah and Israel fought a devastating war in 2006, and its roughly 10,000 peacekeepers are tasked with monitoring the ceasefire between the two sides.