The trucks carrying aid for Gaza stop for exhaustive inspections by Israeli authorities. They can pass through two border crossings only during limited hours. Inside the territory, vehicles travel over a landscape of rubble and ruined roads to distribute the aid to desperate, hungry crowds.

These obstacles are contributing to a growing humanitarian crisis, according to aid officials and two U.S. senators who recently visited Rafah, one of the two crossings into Gaza that is open for aid trucks. Aid groups and the U.N. warn that the risk of famine is widening, that the territory’s health care system is collapsing and that contagious diseases are spreading rapidly.

Israel has been bombarding and besieging Gaza since Oct. 7, when Hamas and other armed Palestinian groups raided Israel, killing about 1,200 people, according to Israeli officials. The war has damaged the roads the trucks use to travel and crippled the communications networks that are essential for coordinating aid distribution. Israel’s siege has dried up almost all the fuel and cut off electricity.

Fighting and Israeli airstrikes have killed about 23,000 people in Gaza, according to health officials in Gaza, including more than 150 aid workers, according to the U.N. and aid groups, who say the war prevents others from being able to report for duty.

Aid groups say the trucks sometimes come under fire from Israeli forces, despite their efforts to coordinate the convoys with the Israeli military in advance.

“The humanitarian community has been left with the impossible mission of supporting more than two million people, even as its own staff are being killed and displaced, as communication blackouts continue, as roads are damaged and convoys are shot at,” Martin Griffiths, the top U.N. humanitarian chief, said in a statement last week.