US, Egyptian, Israeli and Qatari officials are expected to meet in Cairo to seek a truce in Gaza as more than a million civilians crammed into a southern corner of the Palestinian enclave, waiting in fear for an Israeli assault.
Amid growing international concern over the plight of civilians, Israeli tanks shelled the eastern sector of Rafah city overnight, residents said, although the anticipated ground offensive did not appear to have started.
The Israeli military said its forces killed dozens of Palestinian fighters in clashes in the southern and central Gaza Strip in the past 24 hours, including 30 in Khan Younis, a city close to Rafah on the coastal enclave's border with Egypt.
Gaza health officials said an Israeli strike on a house in Nusseirat refugee camp in central Gaza killed 16 Palestinians overnight.
In Khan Younis, Israeli tanks advanced further from the west and the east as bombing continued, residents said.
Israeli forces ordered displaced people in some shelters to head to Rafah.
But the boom of tank shelling east of Rafah caused waves of panic inside the makeshift tent camps housing the displaced.
With the Israel-Hamas war in its fifth month, attention is focused on the situation in Rafah.
About half of Gaza's 2.3 million people are living there in desperate conditions, including many who fled other areas pulverised in Israel's offensive.
Israel says it intends to wipe out the Hamas fighters operating in Rafah and that it plans to evacuate civilians.
Aid officials and foreign governments say there is nowhere for them to go, and Egypt has made clear it will not allow a refugee exodus over its border.
Much of the densely populated enclave is in ruins, with 28,473 Palestinians killed and 68,146 wounded since October 7, according to Gaza health officials who announced 133 new Palestinian deaths in the past 24 hours.
Many other people are believed to be buried under rubble. Supplies of food, water and other essentials are running out and diseases are spreading.
On Monday, US President Joe Biden and Jordan's King Abdullah kept up pressure for a ceasefire.
"The United States is working on a hostage deal between Israel and Hamas which would bring an immediate and sustained period of calm into Gaza for at least six weeks," Biden told reporters in Washington.
The hostages were seized in the October 7 raid on southern Israel by Hamas militants that killed 1200 people and triggered Israel's military offensive.
Securing their return is a priority for Prime Minister Benjamin Netanyahu's government as it aims also to eradicate Hamas, which rules Gaza.
Abdullah underscored the urgency of the plight of the Palestinians, especially those trapped in Rafah.
"We cannot stand by and let this continue," he said. "We need a lasting ceasefire now. This war must end."
In Cairo, senior officials from the US, Egypt, Israel and Qatar were scheduled to meet to work on a three-phase framework that would see the release of hostages and achieve an extended pause, sources familiar with the matter said.
Biden has shown increasing exasperation with Netanyahu for not heeding his appeals to do more to minimise casualties and protect civilians in Gaza.
He has urged Israel not to undertake a ground offensive in Rafah without a plan to protect the Palestinian civilians who are massed there.
Netanyahu last week ordered Israel's military to create a plan to evacuate civilians during any ground offensive.
Asked about those plans, an Israeli military spokesperson on Monday said he still did not know how it would be done.
The United Nations on Monday intensified calls for a ceasefire and opposed the idea of moving civilians in Rafah.
UN spokesman Stephane Dujarric told reporters: "We will not be party to forced displacement of people. As it is, there is no place that is currently safe in Gaza.
"You can't send people back to areas littered with unexploded ordnance, not to mention a lack of shelter."