The world's top court ordered Israel on Thursday to "ensure urgent humanitarian assistance" reaches Gazans, as warnings multiplied of imminent famine after nearly six months of relentless conflict.

Heavy fighting and sustained bombardment again rocked the territory despite the UN Security Council's adoption of a resolution earlier this week demanding an "immediate ceasefire."

"Israel shall... take all necessary and effective measures to ensure, without delay... the unhindered provision... of urgently needed basic services and humanitarian assistance," the International Court of Justice said in its ruling.

This included food, water, electricity, fuel, shelter, clothing, hygiene and sanitation requirements, as well as medical supplies and medical care to Palestinians throughout Gaza, its judges said.

"Palestinians in Gaza are no longer facing only a risk of famine, but... famine is setting in," the Hague-based court said.

South Africa had asked the court to bolster a previous order it issued in January for Israel to allow aid into Gaza to take account of the further deterioration of the situation on the ground.

The United Nations has warned that famine "is ever closer to becoming a reality in northern Gaza," and said Gaza's health system is collapsing "due to ongoing hostilities and access constraints."

While the war has turned much of the territory into a devastated wasteland, Israel has also imposed a siege on its 2.4 million people, eased only by occasional aid deliveries.

With clean water also scarce, Gazans were queueing to fill plastic containers from a tank west of Rafah city.

"We have to queue for everything," said one displaced woman, Maram Abu Amra. "We walk for an hour in total. Sometimes, we return empty-handed, without water."

The war began with Hamas's October 7 attack that resulted in about 1,160 deaths in Israel, mostly civilians, according to a tally based on Israeli official figures.

The militants also took about 250 hostages. Israel says about 130 captives remain in Gaza, including 34 presumed dead.

Israel's retaliatory campaign has killed at least 32,552 people, mostly women and children, according to Gaza's health ministry. (AFP)