CAIRO/GAZA: The United Nations on Tuesday demanded an immediate humanitarian ceasefire in the Gaza Strip as U.S. President Joe Biden warned Israel it was losing international support because of its "indiscriminate" bombing of civilians in its war against Hamas.

After dire warnings by U.N. officials about a deepening humanitarian crisis in Gaza, the 193-member U.N. General Assembly passed a resolution calling for a ceasefire with 153 countries voting in favour and 23 abstaining. The U.S. and Israel, which argue a ceasefire only benefits Hamas, voted against the measure along with eight other countries.

The resolution is not binding but carries political weight, reflecting a global view on the war. The United States vetoed a similar call in the 15-member Security Council last week.

The Palestinian Authority welcomed the resolution and urged countries to pressure Israel to adopt the ceasefire. A Hamas official in exile, Izzat El-Reshiq, in a statement on Telegram echoed that reaction, saying Israel should "stop its aggression, genocide, and ethnic cleansing against our people."

Before the resolution passed, Biden said Israel now has support from "most of the world" including the U.S. and European Union. "But they're starting to lose that support by indiscriminate bombing that takes place," he told a campaign donor event in Washington.

Israel's assault on Gaza to root out Hamas has killed at least 18,205 Palestinians and wounded nearly 50,000 since Oct. 7, according to the Gaza health ministry.

Israel launched its onslaught after a cross-border raid by Hamas fighters who killed 1,200 people and took 240 hostage in southern Israel on Oct. 7. Israel on Tuesday declared 19 of 134 people still in captivity in Gaza dead in absentia after the bodies of two hostages were recovered.

In Khan Younis, southern Gaza's main city, residents said on Tuesday Israeli tank shelling was now focused on the city centre. One said tanks were operating in the street where the house of Yahya Al-Sinwar, Hamas' leader in Gaza, is located.

After nightfall, Israeli air strikes on Khan Younis in southern Gaza Strip killed 11 Palestinians, including two children, health officials said.

An older Palestinian, Tawfik Abu Breika, earlier said his residential block in Khan Younis was hit without warning by an Israeli air strike that brought down several buildings and caused casualties.

"The world’s conscience is dead, no humanity or any kind of morals," Breika told Reuters as neighbours sifted through rubble. "This is the third month that we are facing death and destruction."

Further south in Rafah, which borders Egypt, health officials said an Israeli air strike on houses overnight killed 22 people, including children. Civil emergency workers were searching for more victims under the rubble.

Residents said the shelling of Rafah, where the Israeli army this month ordered people to head for their safety, was some of the heaviest in days.

"At night we can’t sleep because of the bombing, and in the morning, we tour the streets looking for food for the children. There is no food," said Abu Khalil, 40, a father of six.

The U.N. World Food Programme says half of Gaza's population is starving. "There’s no electricity, no fuel, no water, no medicine," resident Mohammed Obaid said as he inspected debris in Rafah.

The Gaza health ministry said that diseases and illnesses including diarrhea, food poisoning, meningitis, respiratory infections, chickenpox and scabies were spreading.

LOSING SUPPORT

In addition to warning that Israel was starting to lose international support, Biden said that Israeli Prime Minister Benjamin Netanyahu needed to change his hard-line government and that ultimately Israel "can't say no" to an independent Palestinian state - something that Israeli hardliners oppose.

In a further sign of world concern over the conduct of the conflict, now in its third month, Australia, Canada and New Zealand said they supported international efforts toward a sustainable ceasefire and expressed alarm at the plight of civilians in Gaza.

"The price of defeating Hamas cannot be the continuous suffering of all Palestinian civilians," leaders of the three countries said in a joint statement.

The three countries said they supported Palestinians' right to self-determination, but that there could be no role for Hamas in the future governance of Gaza.

ROCKET FIRE

Israel's military said that over the past day it hit several posts that were used to fire rockets at its territory, raided a Hamas compound where it found some 250 rockets among other weapons and struck a weapons production factory.

The ground assault that started in the north has expanded to the southern half of the Gaza Strip since a week-long truce collapsed at the start of December. More than 100 Israeli soldiers have been killed in Gaza since the ground invasion began in late October.

The Wall Street Journal and ABC reported that the Israeli military has begun pumping seawater into Hamas' tunnel complex, where the group is believed to be hiding fighters and munitions and basing hit-and-run attacks on Israeli troops in street fighting.

Biden said he had heard unconfirmed reports there were no hostages in the tunnels. Some hostages freed during a ceasefire reported they had been held in tunnels. The Israeli military said it was looking into the reports.

Gaza health ministry spokesperson Ashraf Al-Qidra said Israeli forces had raided Kamal Adwan Hospital in northern Gaza on Tuesday and detained its director, Dr. Ahmed Al-Kahlout, along with all medical staff.

They were being interrogated within the emergency department, he said. Israel's military did not reply to a request for comment on the incident.