Israel on Friday gave Palestinians 24 hours to leave Gaza City ahead of an expected ground offensive in retaliation against Hamas for the deadliest attack in Israeli history.
The United Nations said it had been informed of the evacuation order shortly before midnight Thursday, six days after hundreds of Hamas gunmen broke through the militarised border barrier around the Gaza enclave and killed more than 1,200 people in Israel, drawing comparisons to the 9/11 attacks on the United States.
The UN said the mass relocation, affecting 1.1 million or about half the entire population of the Gaza Strip, to the territory's south was "impossible" and urgently appealed for the order to be rescinded.
Any Israeli ground operation is complicated by Hamas's holding -- according to Israel's government -- of around 150 Israeli, foreign and dual-national hostages.
Hamas on Friday said 13 hostages, including foreigners, had been killed in Israeli strikes. They had previously reported four hostages killed in strikes, and the latest deaths came at "five locations targeted by Israeli fighter jets", said the movement, listed as a terrorist organisation by the United States and Europe.
Israel has retaliated by hitting targets in Gaza with thousands of munitions, in strikes claiming more than 1,530 lives -- 500 of them children, according to the health ministry in Gaza.
The Israeli army confirmed Friday it had called on Gaza City residents to move "to the area south of the Wadi Gaza", which is just below Gaza City in the 40 km-long (25 miles) territory.
"In the following days, the IDF will continue to operate significantly in Gaza City and make extensive efforts to avoid harming civilians," the army said. "Hamas terrorists are hiding in Gaza City inside tunnels underneath houses and inside buildings populated with innocent civilians."
UN officials working in Gaza said earlier they were informed by the Israeli military that the evacuation should be carried out "within the next 24 hours".
AFP correspondents said there were "heavy strikes" in the northern Gaza Strip on Friday morning, including Al-Shati refugee camp and Gaza City, primarily targeting residential buildings.
The Hamas media office reported Israeli air raids on Khan Yunis and Rafah in the south.
Israel's army said its "fighter jets struck 750 military targets in the northern Gaza Strip overnight" including "residences of senior terrorist operatives used as military command centres".
Israel says it seeks to eliminate the capability of Hamas, which itself wants Israel's destruction and said its attack Saturday sought to end Israel's "rampaging without being held accountable".
Hamas, in a statement, said "our Palestinian people" rejected Israel's Gaza evacuation order.
Carrying plastic bags of belongings, with suitcases on their shoulders and children in their arms, Gazans were, however, moving to safer areas on Friday.
More than 423,000 people have already fled their homes in the territory, according to the UN.
Such an evacuation order could transform "what is already a tragedy into a calamitous situation," a UN spokesman said.
The UN Relief and Works Agency for Palestine Refugees (UNRWA) later said it had moved its central operations centre and international staff to the south of Gaza.
'Very Painful'
Gaza's 2.4 million residents are enduring the fifth war in 15 years.
Israeli fighter jets and drones have levelled entire blocks and destroyed thousands of buildings.
The territory had already been under a land, air and sea blockade since 2006.
Israel has cut off water, food and power supplies to Gaza in a total siege it has vowed will not end until all hostages are freed.
Hamas has threatened to kill captives if Israel bombs Gaza civilian targets without advance warning.
"I know he's out there somewhere," a distraught Israeli, Ausa Meir, said of her brother Michael, who is among the captives.
"It's very, very painful."
US Support
The United States has vowed unwavering support for Israel in its war on Hamas.
"You may be strong enough on your own to defend yourself," US Secretary of State Antony Blinken said at a joint press conference in Tel Aviv with Prime Minister Benjamin Netanyahu on Thursday.
"But as long as America exists, you will never, ever have to. We will always be there by your side."
Netanyahu voiced appreciation for the US support, which includes additional military aid, and said Hamas, which rules the Gaza Strip, should be "crushed" like the Islamic State group.
Blinken stressed Hamas did not represent the Palestinian people.
Blinken then travelled to Jordan, where he will meet King Abdullah II and Palestinian leader Mahmud Abbas on Friday.
He will also go to Saudi Arabia, Egypt, the UAE and Qatar to put pressure on Hamas and secure the release of hostages.
Hospital Morgues
The International Committee of the Red Cross Middle East chief Fabrizio Carboni warned Gaza's hospitals "risk turning into morgues".
An uninterrupted stream of ambulances arrived Thursday at Gaza's biggest hospital, Al-Shifa, where relatives of the dead wailed in anguish and others sought news of loved ones.
An AFP team saw dozens of bodies wrapped in white shrouds in cold storage units and covering the floor of the mortuary.
The UN humanitarian agency has launched an urgent appeal for nearly $300 million to address the most urgent needs in Gaza and the occupied West Bank.
Military Build-up
Israel has called up 300,000 reservists and rushed forces, tanks and heavy armour to the southern desert areas around Gaza from where Hamas fighters launched their attack on Saturday.
Israeli soldiers have since then swept the southern towns and kibbutz communities and said they found the bodies of 1,500 operatives, while making ever more shocking discoveries of large numbers of dead civilians.
Yossi Landau, who has 33 years' volunteer experience with Zaka, which recovers the bodies of people who suffered unnatural deaths, says he has almost reached breaking point recovering the remains of those killed by Gaza groups.
In Beeri, a community just north of Gaza, he recalled finding a dead woman in a home.
"Her stomach was ripped open, a baby was there, still connected with the cord, and stabbed," said Landau.
They were among more than 100 people killed in Beeri, while around 270 were gunned down or burned in their cars at the nearby Supernova music festival.
Hamas denied its operatives killed infants during the attack on Saturday.
Hezbollah Threat
Israel's war now flaring in the south is further complicated by a threat from the north, the Iran-backed Hezbollah group based in Lebanon.
The army has massed tanks on the border after repeated clashes with Hezbollah in recent days, including cross-border rockets and shelling.
The United States has sent additional munitions to Israel and deployed an aircraft carrier battle group to the eastern Mediterranean in a show of support, while warning Israel's other enemies not to enter the war.
Defence Secretary Lloyd Austin arrived in Israel on Friday on a visit also aimed at showing solidarity, after Blinken's stop.
In London, the UK said it was sending two Royal Navy ships and surveillance aircraft to the eastern Mediterranean to support Israel, as well as "ensure regional stability and prevent further escalation".
Israel's arch foe Iran has long financially and militarily backed Hamas and praised its attack, but insists it was not involved.
The Washington Post reported that US and Qatari officials have agreed to prevent Iran from using a $6 billion humanitarian assistance fund, following the Hamas attack.
"The US government knows that it can NOT renege on the agreement," Ali Karimi Magham, spokesperson of Iran's permanent mission to the United Nations, said late Thursday in a post on X, formerly Twitter.
Thousands of Iranians took to the streets on Friday in a sign of support for the Palestinians. A similar number demonstrated in the Iraqi capital Baghdad where they chanted, "No to the occupation! Not to America!"
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
