Israeli warplanes and artillery pounded Rafah, after the government dismissed an order by the top UN court to halt its military offensive in the southern Gaza city.
At the same time, questions remained over the resumption of truce talks despite renewed international efforts aimed at securing a prisoner-hostage exchange and ceasefire in the war sparked by Palestinian militant group Hamas's unprecedented October 7 attack on Israel.
An Israeli official said Saturday the government had an "intention" to restart stalled negotiations over the coming days.
But a senior member of Hamas later told Al Jazeera he had not been "informed of anything by the mediators in this context".
In a case brought by South Africa alleging the Israeli military operation amounts to "genocide", the International Court of Justice ordered Israel to halt its Rafah offensive, and demanded the release of hostages and the "unhindered provision" of humanitarian aid into Gaza.
The Hague-based ICJ, whose orders are legally binding but lack direct enforcement mechanisms, also instructed Israel to keep open the Rafah crossing between Egypt and Gaza, after Israel's seizure of the Palestinian side earlier this month effectively shut it.
Israel gave no indication it was preparing to change course in Rafah, insisting the court had got it wrong.
The ruling said Israel must "immediately halt its military offensive, and any other action in the Rafah governorate, which may inflict on the Palestinian group in Gaza conditions of life that could bring about its physical destruction in whole or in part".
But National Security Adviser Tzachi Hanegbi, in a joint statement with the foreign ministry, said: "Israel has not and will not carry out military operations in the Rafah area that create living conditions that could cause the destruction of the Palestinian civilian population, in whole or in part."
Hamas, the Iran-backed Islamist group that has ruled Gaza since 2007, welcomed the ruling but criticised the court's decision to exclude the rest of the Palestinian territory from its order.
- 'Nothing left' -
Israel carried out strikes throughout the Gaza Strip on Saturday and into Sunday morning as fighting raged between the army and Palestinian militants.
Witnesses and AFP teams reported strikes or shelling on Saturday in Rafah, the central city of Deir al-Balah, and Gaza City and the Jabalia refugee camp in the north.
In Gaza City, an AFP photographer saw a grieving woman embracing one of several bodies, some of them children, which were shrouded in blood-stained white cloth and laid on the ground outside a clinic ahead of funerals.
They were killed in a strike on a school turned shelter in nearby Jabalia, relative Saleh al-Aswad told AFP.
Witnesses also reported heavy shelling in Rafah and air strikes elsewhere in the Strip early Sunday, according to an AFP journalist on the ground.
Umm Mohammad Al-Ashqa, displaced from Gaza City to Deir al-Balah by the war, told AFP Saturday she hoped "the court's decision will put pressure on Israel" to end the fighting, "because there is nothing left here".
The ICJ ruling came as arrest warrants for Israeli and Hamas leaders were pending at the International Criminal Court, and after three European governments said they would formally recognise the State of Palestine.
The war broke out after Hamas's October 7 attack, which resulted in the deaths of more than 1,170 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Militants also took 252 hostages, 121 of whom remain in Gaza, including 37 the army says are dead.
Israel's retaliatory offensive has killed at least 35,903 people in Gaza, mostly civilians, according to the Hamas-run territory's health ministry.
- 'I feared this moment' -
Diplomatic efforts have resumed to seek the first ceasefire in Gaza since a week-long truce and hostage release in November.
An Israeli official, requesting anonymity to discuss the negotiations, told AFP that "there is an intention to renew these talks this week, and there is an agreement".
However, senior Hamas official Osama Hamdan later said in an interview with Al Jazeera: "Until now, there is nothing practical on this issue. It is just talk coming from the Israeli side."
Israeli Prime Minister Benjamin Netanyahu's government has come under increasing domestic pressure over the fate of the hostages, with demonstrators rallying again in Tel Aviv on Saturday.
The official did not elaborate on the agreement, but Israeli media said intelligence chief David Barnea had agreed a new framework for negotiations in a meeting with US and Qatari mediators in Paris.
Speaking at the US military academy West Point, President Joe Biden said his administration was engaged in "urgent diplomacy to secure an immediate ceasefire that brings hostages home".
Mediator Egypt was continuing "its efforts to reactivate ceasefire negotiations", said Al-Qahera News, which has links with Egyptian intelligence.
Meanwhile, Hamas's armed wing said it had taken "prisoner" at least one Israeli soldier in an ambush in a tunnel in Jabalia camp on Saturday.
In a statement on Telegram, however, the Israeli army said it "clarifies that there is no incident in which a soldier was abducted".
In Tel Aviv, a crowd of several thousands observed a minute of silence Saturday for dead captives, an AFP correspondent reported, after the army said troops had retrieved seven bodies in recent raids.
"I feared this moment," said Avivit Yablonka, whose brother Chanan was brought back dead from Gaza.
"I will continue to shout, support, fight and do everything so that all the hostages return home," she told the rally.
- Internet down -
Israeli forces entered Rafah in early May, taking over the Palestinian side of its border crossing and prompting an exodus of more than 800,000 people, according to UN figures.
The White House said Egypt had agreed to temporarily send UN aid through another crossing, Kerem Shalom near Rafah, on Gaza's border with Israel.
Al-Qahera said Egypt was exerting "pressure on Israel to urgently let in the aid and fuel" stranded at the Rafah crossing, and mentioned "temporary measures" to provide Gazans with humanitarian relief.
The UN has warned of famine in the besieged territory, where most hospitals are no longer functioning.
The Kuwaiti Hospital in Rafah pleaded for fuel deliveries to ensure the "continued operation" of the only medical facility in the area still receiving patients.
Telecommunications operator Paltel said internet access in northern Gaza was disrupted on Saturday "due to the ongoing aggression".
The US military said four of its vessels, supporting a temporary pier built to deliver aid to Gaza by sea, had run aground in heavy seas.
"No US personnel will enter Gaza. No injuries have been reported and the pier remains fully functional," a statement from US Central Command.