Israel reopened an aid crossing into Gaza on Friday as key backer the United States urged more restraint in its all-out offensive against Hamas.

The war began after Hamas launched an unprecedented attack on Israel on October 7 that Israeli officials say killed around 1,200 people, mostly civilians.

Vowing to destroy Hamas and bring home an estimated 250 hostages taken by militants into Gaza, Israel launched a massive military offensive that has left much of the besieged territory in ruins.

The health ministry in the Hamas-run Gaza Strip says the war has killed more than 18,700 people, mostly women and children.

Fierce fighting continued on Friday, with Hamas claiming they had blown up a house containing Israeli soldiers in the city of Khan Younis.

Further south in Rafah near the Egyptian border, crowds of Palestinians used flashlights to search the rubble of buildings for survivors following Israeli strikes.

"This is a residential neighbourhood, women and children live here, as you can see," said resident Abu Omar. "Three missiles on a residential neighbourhood that has nothing to do with any militant activities."

Multiple rockets were intercepted over Jerusalem by its powerful missile-defence system.

Under pressure to do more to spare civilians, Israel announced it would allow the "temporary" entry of aid into Gaza through a second crossing, at Kerem Shalom near Rafah, the only other point of entry for humanitarian supplies. (AFP)