Israeli Prime Minister Benjamin Netanyahu told residents of Gaza City on Monday to evacuate, as the military ramped up its deadly assault on the Palestinian territory's largest urban centre.
Israel has been intensifying its bombardment of the city in preparation for an operation to conquer it, despite repeated entreaties from Western nations and aid agencies to stop.
Gaza's civil defence agency meanwhile said at least 39 people had been killed by Israel, including 25 in Gaza City, Monday.
The premier's warning came hours after one of the deadliest attacks on civilians in Jerusalem since the start of the war, in which two Palestinian gunmen opened fire on a bus, killing six people, according to Foreign Minister Gideon Saar.
The two gunmen were killed by a security officer and an armed civilian, police said.
Israel's defence minister, Israel Katz, had told Hamas earlier Monday to lay down its arms or face annihilation.
On Monday, Israeli forces targeted a fourth high-rise building - the Al-Ruya tower- in Gaza City in as many days.
Israel has faced mounting international pressure to halt its campaign in Gaza, with United Nations rights chief Volker Turk saying he was "horrified by the open use of genocidal rhetoric... by senior Israeli officials".
US news outlet Axios reported that White House envoy Steve Witkoff sent a new proposal for a Gaza hostage and ceasefire deal to Hamas last week.
Palestinian fighters killed four Israeli soldiers Monday after lobbing an explosive device into their tank, the Israeli military said.
A Reuters report said Spain on Monday banned ships and aircraft carrying weapons to Israel from calling at Spanish ports or entering its airspace due to Israel's military offensive in Gaza, measures the Israeli foreign minister denounced as antisemitic.
Spain, which recognised a Palestinian state in May 2024 and has been a vocal critic of Israel's actions in the Gaza Strip, responded to Gideon Saar's comments by summoning its ambassador in Tel Aviv back for consultations.
On top of the ban on ships and aircraft delivering weapons or military-grade jet fuel to Israel, Prime Minister Pedro Sanchez's government said it would not allow anyone who has participated directly in "genocide" in Gaza to enter Spain.
Israel has strongly denied that its actions in Gaza amount to genocide, and it is fighting a case at the International Court of Justice in the Hague that accuses it of genocide.
Palestinians cry as they walk outside al-Shifa hospital in Gaza City where casualties of early Israeli strikes were transported, on Monday. AFP
A boy reacts during the funeral of Palestinians killed in overnight Israeli strikes, according to medics, at Al-Shifa Hospital in Gaza City, Monday. REUTERS
The al-Ruya Tower in Gaza City's Rimal area collapses amidst smoke after Israeli bombardment, on Monday. AFP
A displaced Palestinian stands next to packed belongings amid an Israeli military operation, in Gaza City, Monday.
Palestinians check the rubble of al-Ruya Tower in Gaza City following Israeli army bombardment, Monday.