Overnight bombing on Rafah killed around 100 people, including children, said the health ministry of the Hamas-run Gaza Strip.
Hamas officials said 14 houses and three mosques were hit.
Fears of an Israeli ground invasion are growing among more than a million Palestinians trapped in the southern Gaza Strip.
The bloodiest ever Gaza war broke out after Hamas launched an unprecedented attack on southern Israel on October 7 that resulted in the deaths of about 1,160 people, mostly civilians, according to an AFP tally based on official figures.
Israel has responded with a relentless offensive in Gaza that the territory's health ministry says has killed at least 28,340 people, mostly women and children.
