Thousands of tonnes of "life and death" aid for Gaza should be delivered soon, the United Nations said Friday, to relieve a "beyond catastrophic" situation after unrelenting Israeli bombing in response to an unprecedented Hamas attack.

Some 175 lorries stuffed with vital medicines, food, and water stretched into the distance at the Rafah crossing with Egypt, which has removed concrete roadblocks and is scrambling to repair the route into besieged Gaza — the only one not controlled by Israel.

Overseeing operations personally, UN Secretary-General Antonio Guterres told reporters: "These trucks are not just trucks, they are a lifeline, they are the difference between life and death for so many people in Gaza."

Israel has vowed to destroy Hamas after the Islamist militant group launched a shock raid from the Gaza Strip on October 7, killing at least 1,400 people, mostly civilians shot, mutilated or burned to death, according to Israeli officials.

Hamas gunmen also kidnapped some 200 hostages including foreigners from around two dozen countries.

The Islamist group said Friday that its armed wing had released two Americans among the captives, a mother and her daughter, the first fruit of mediation efforts by the Gulf state of Qatar.

The Islamist group did not detail how or when the hostages were released.

The Israeli military said earlier Friday that most of those abducted to Gaza were still alive. It said more than 20 were minors.

In response to the Hamas attack, Israeli bombers have levelled entire city blocks in Gaza in preparation for a ground invasion they say is coming soon. The Hamas-run health ministry said 4,137 Palestinians, mostly civilians, have died in the onslaught.

Israeli jets pounded more than 100 Hamas targets in Gaza overnight, the army said, with AFP reporters hearing loud explosions and witnessing plumes of smoke billowing from the northern Gaza Strip.

Embracing front-line soldiers and clad in body armour, Israel's Prime Minister Benjamin Netanyahu urged them to "fight like lions" and "win with full force".

Fists clenched and voice raised, Netanyahu told cheering troops: "We will deal harsh blows to our enemies in order to achieve victory."

Defence Minister Yoav Gallant told some of the tens of thousands of personnel preparing the ground invasion that "the order will come soon".

'Beyond catastrophic' 

US President Joe Biden said Friday he expected the first aid for Gaza to pass through the Rafah crossing from Egypt within the next two days, under a deal he clinched to allow in 20 trucks of supplies for civilians.

Medicine, water purifiers and blankets were being unloaded at El Arish airport near Gaza, an AFP reporter saw, with Ahmed Ali, head of the Egyptian Red Crescent, saying he was getting "two to three planes of aid a day".

But World Health Organization emergencies director Michael Ryan said Biden's 20-truck deal was "a drop in the ocean of need" and that 2,000 trucks were required.

The UN says more than one million of Gaza's 2.4 million people are displaced, with the humanitarian situation "beyond catastrophic" and deteriorating daily.

Refugees from northern Gaza told harrowing tales of bombs, profiteering and extreme temperatures as whole families trekked on foot to flee the violence.

Mother of seven Fadwa Al-Najjar walked for 10 hours with her family from northern Gaza to reach a UN camp in the southern city of Khan Yunis, saying she saw cars hit by a strike just in front of them.

"We saw bodies and limbs torn off and we just started praying, thinking we were going to die," she said.

'It's unimaginable' 

On the other side of the conflict, the full horror of what Israel suffered on October 7 and following days was still emerging, as traumatised residents recounted their stories.

Shachar Butler, a security chief at the Nir Oz kibbutz, where Hamas militants killed or kidnapped a quarter of the 400 residents, recalls more than a dozen gunmen spraying bullets indiscriminately and lobbing grenades at homes.

"It's unimaginable," the 40-year-old told AFP as part of a trip organised by the Israeli military.

"Anytime someone tried to touch my window, I shot him," he said. "The people who came out got kidnapped, killed, executed, slaughtered."

Butler estimated as many as 200 militants attacked the kibbutz, entering from three sides before going house-to-house. Homes there were still charred with burnt personal belongings strewn everywhere.

Israel says around 1,500 Hamas fighters were killed in clashes before its army regained control.

'No safe place' 

Biden requested a massive $105 billion security package Friday, including $14 billion for Israel, but paralysis in the still speakerless Congress means it will hit an immediate wall.

Fresh from a whirlwind trip to Israel this week, Biden is hoping to staunch the possibility of a wider Middle East war.

The United States has moved two aircraft carriers into the eastern Mediterranean to deter Iran or Lebanon's Hezbollah, both Hamas allies, from getting involved.

After days of clashes with Hezbollah fighters along the Lebanese border, Israeli authorities announced the evacuation of Kiryat Shmona, a nearby town which is home to some 25,000 residents, many of whom have already left.

The conflict has inflamed passions across the region, with protests held in several countries.

Thousands flooded into Egypt's iconic Tahrir Square in support of Gaza, an AFP correspondent said. Protests were also held outside the French and US embassies in Tunis.

Following a strike at a church compound late Thursday, the Hamas-controlled interior ministry said several people sheltering at the church were killed and wounded, blaming an Israeli strike.

The Israeli army acknowledged a church wall had been damaged in one of its air strikes targeting a "command and control centre belonging to a Hamas terrorist".

"This place is dedicated for praying, a place of love and peace," said witness Abu Khalil Jahshan. "There is no safe place here in Gaza."