Hamas warned Israel on Sunday that a ground offensive in Rafah, crowded with displaced Gazans, would imperil future hostage releases, as the Hamas-run territory's health ministry said at least 52 people were killed in heavy air strikes before dawn on Monday.
The strikes hit 14 houses and three mosques in different parts of Rafah, according to the Hamas government.
The threat of an Israeli incursion into Gaza's southernmost town of Rafah persisted Sunday, but Israeli Prime Minister Benjamin Netanyahu promised "safe passage" to civilians displaced there.
In an interview airing Sunday, Netanyahu reiterated his intention to extend Israel's military operation against Hamas into Rafah.
U.S. Secretary of State Antony Blinken will kick off another Mideast crisis tour on Monday in a bid to secure a new truce in the Israel-Hamas war, as southern Gaza saw no let-up in fighting.
On his fifth trip to the region since Hamas's Oct. 7 attack that triggered the war, Blinken is expected to visit Saudi Arabia, Israel, Egypt and Qatar.