The UN agency for Palestinians, UNRWA, suspended its food distribution service in the southern city of Rafah on Tuesday, in the latest disruption to aid services in Gaza.
UNWRA said it has run out of food and Israeli attacks on the city have made it too dangerous to operate, forcing it to halt services, which more than half of Gaza's population depend on.
Israel's incursion into the southern areas has disrupted aid channels after it closed the Rafah and Kerem Shalom border gates, blocking supplies from entering the war-torn enclave for over ten days.
Aid agencies have said the population is at greater risk of famine while medics have said hospitals are rapidly running out of supplies.
Fighting in north Gaza saw Israeli forces push deeper into Jabalia camp in battles with Palestinian militants on Tuesday. Neighbourhoods have suffered major damage and dozens of civilians have been hit.
Residents and medical officials said Israeli tanks were besieging the Al-Awda Hospital in Jabalia for the third day, and opened fire against Kamal Adwan hospital in nearby Beit Lahiya town, medics said.