The Israeli military said on Wednesday it had struck a Hamas site in northern Gaza, where it had detected preparations for firing into Israeli territory.
On Tuesday, Israeli air strikes killed more than 400 people, according to Palestinian health authorities, in one of the highest single-day death tolls since the beginning of conflict, with Israel warning the onslaught was "just the beginning".
Israel and Hamas accuse each other of breaching the truce, which had offered a respite for Gaza's 2.3 million residents after 17 months of war that has reduced the enclave to rubble and forced the majority of its population to displace multiple times.
On Wednesday, the Israeli army dropped leaflets on areas in Beit Hanoun and Khan Younis in the northern and southern Gaza Strip, ordering residents to evacuate their homes, warning they were in "dangerous combat zones."
"Staying in the shelters or the current tent puts your lives and that of your family members in danger, evacuate immediately," a leaflet dropped on Beit Hanoun said.
Israeli Prime Minister Benjamin Netanyahu said on Tuesday that he had ordered strikes because Hamas had rejected proposals to secure an extension of the ceasefire until April.
Hamas, which still holds 59 of about 250 hostages Israel says the group seized in its October 7, 2023, cross-border attack, accused Israel of jeopardising efforts by mediators to negotiate a permanent deal to end the fighting.
European Union foreign policy chief Kaja Kallas said on Wednesday that she told Israeli Foreign Minister Gideon Saar that the situation in Gaza is "unacceptable".
"Yesterday I also talked to Foreign Minister Saar ...what is happening, why are you doing this. And I mean, also conveying the message that this is unacceptable," she told reporters in Brussels.
German Foreign Minister Annalena Baerbock on Wednesday called for restraint from all sides ahead of her trip to Lebanon to discuss the conflict.
Israel and Western powers do not want the Palestinian militant group Hamas to play any role in the enclave when the war is over. Israel has vowed to crush Hamas, but the Palestinian militant group remains the dominant force in Gaza.
Arab nations drew up a plan for peace and reconstruction in Gaza after a proposal from US President Donald Trump to resettle Palestinians and turn it into the "Riviera" of the Middle East triggered outrage in the region. However, the plan has not gained traction.
In Wednesday's violence, three people were killed in an Israeli air strike on a house in the Sabra suburb in Gaza City, while another air strike left two men dead and wounded six others in Beit Hanoun town in the north, the Gaza health officials said.
Palestinian medics said Israeli tank shelling on the Salahdeen road killed one Palestinian and wounded others, raising the death toll to 416 since the new Israeli campaign began, according to health authorities.
Israeli naval vessels also attacked several boats, which Israel said intended to carry out "terrorist" acts by Hamas and Islamic Jihad militant groups.
Palestinians said an Israeli drone fired at several fishing boats onshore of Gaza City, setting several of them ablaze.
Hamas officials said they remained keen on concluding the three-phase ceasefire deal as signed.
Hamas-led gunmen attacked Israel on October 7, 2023, killing some 1200 people and taking about 250 hostages, according to Israeli tallies.
The subsequent Israeli campaign in Gaza has killed nearly 49,000 people, say Palestinian health authorities.
