Israeli forces struck the southern Gaza town of Rafah twice overnight, residents said, sowing fear in one of the last places where civilians could seek refuge after Israel widened its offensive against Hamas to areas already packed with displaced people.

United Nations officials say there are no safe places in Gaza.

Heavy fighting in and around the southern city of Khan Younis has displaced tens of thousands of people in a territory where more than 80% of the population have already fled their homes, and cut most of Gaza off from deliveries of food, water and other vital aid.

Two months into the war, the grinding offensive has set off renewed alarms internationally, with UN secretary-general Antonio Guterres using a rarely exercised power to warn the Security Council of an impending “humanitarian catastrophe” and urging members to demand a ceasefire.

The United States has called on Israel to limit civilian deaths and displacement, saying too many Palestinians were killed when it obliterated much of Gaza City and the north.

But President Joe Biden’s administration, which has pledged unwavering support for Israel, appeared likely to block any such UN effort to halt the fighting.

Israel says it must crush Hamas’s military capabilities and remove it from power following the October 7 attack that ignited the war.

Troops have pushed into Khan Younis, Gaza’s second-largest city, which Israeli officials have portrayed as Hamas’s centre of gravity – something they previously said was in Gaza City and its Shifa Hospital.

Israel has ordered the evacuation of some two dozen southern neighbourhoods, rather than the entire region as it did in the north, which the military says shows increased concern for civilians.

But the areas where Palestinians can seek safety are rapidly receding.

With northern and central Gaza largely isolated and cut off from aid, Palestinians are heading south to Rafah and other areas along the border with Egypt, where family homes are packed tight and makeshift shelters are overflowing.

Even there, safety has proven elusive, as Israel continues to strike what it says are Hamas targets across the coastal enclave.

A strike late on Wednesday levelled a home in Rafah, sending a wave of wounded streaming into a nearby hospital.

Eyad al-Hobi, who witnessed the attack, said around 20 people were killed, including women and children.

Another house was hit early on Thursday, residents said.

“We live in fear every moment, for our children, ourselves, our families,” said Dalia Abu Samhadaneh, now living in Rafah with her family after fleeing Khan Younis.

“We live with the anxiety of expulsion.”

The military meanwhile accused militants of firing rockets from open areas near Rafah in the humanitarian zone.

It released footage of a strike on Wednesday on what it said were launchers positioned outside the town and a few hundred metres from a UN warehouse.