A four-day truce in the Israel-Hamas war began on Friday, with hostages set to be released in exchange for prisoners in the first major reprieve in seven weeks of war that have claimed thousands of lives.

The two sides had agreed to silence guns and stop bombings from 7:00 am (0500 GMT) in a conflict that erupted after Hamas's murderous raids into Israel on 7 October.

As part of the agreement, 13 women and children held hostage in Gaza are due to be freed at 4:00 pm (1400 GMT), followed by a number of Palestinian prisoners from Israeli jails, according to Qatari mediators.

Over the four days, at least 50 hostages are expected to be released, leaving an estimated 190 in the hands of Palestinian militants.

In exchange, 150 Palestinians prisoners are expected to be released.

For Gaza's two million-plus residents, the deal brings a promise of respite from weeks of sustained Israeli bombardment.

The territory's Hamas government says the war has so far killed about 15,000 people and displaced countless more.

At dawn, thousands of people who had fled to areas near Gaza's border with Egypt were preparing to return to their villages.

Minutes after the truce took effect, 16-year-old Omar Jibrin emerged from a hospital in the south of the territory where he and eight family members had sought refuge.

"I'm going home," he told AFP as he began the journey.

However, Israeli warplanes over southern Gaza dropped leaflets warning people not to head back to the north.

"The war is not over yet," the leaflets read. "Returning to the north is forbidden and very dangerous!!!"

Around 15 minutes after the truce began, sirens warning of incoming rockets sounded in several communities along Israel's border with Gaza, the Israeli military said, without providing further details.

The exact number of casualties in the war is impossible to independently confirm, but for many Palestinian and Israeli families, the truce came too late.

"The last thing he said to me was that he was waiting for the truce on Friday," Fida Zayed, a Gazan whose 20-year-old son Udai was killed in a recent air strike, told AFP.

"The living here are the ones who are dead."

Preparing for the worst

Qatari officials said the "first batch" of 13 hostages released would be women and children from the same families.

Speaking to AFP on condition of anonymity, a Hamas official said the hostages would be released "by 4:00 pm at the latest".

Teams of Israeli trauma experts and medics await them — along with specially trained soldiers who, according to guidelines, will promise to keep them safe.

They will also carry a child's favourite food item, be it pizza or chicken schnitzel.

An Egyptian security source told AFP that Israeli security officials, International Red Cross-Red Crescent staff and an Egyptian team would deploy to Rafah, on the Egypt-Gaza border, to receive the hostages, who will then be flown to Israel.

AFP has confirmed the identities of 210 of the roughly 240 people abducted during cross-border attacks by Hamas on military posts, communities and a desert music festival.

At least 35 of those taken hostage were children, with 18 of them aged 10 or under at the time of the Hamas attack.

Israel says around 1,200 people, mostly civilians, were killed in the October 7 attacks.

Little is publicly known about which hostages remain alive, or in what conditions the hostages have been held.

"Given the barbaric nature of the attacks and captivity we can only prepare for worst-case scenarios," said Moty Cristal, a retired Israeli military official with experience in hostage negotiations.

The office of Israeli Prime Minister Benjamin Netanyahu said it had received "a first list of names" of those due to be released and been in contact with the families. It did not specify who was on the list.

"We've already been on an emotional roller coaster for 47 days and today is no different," said Eyal Kalderon, a cousin of Ofer Kalderon, who is among those held captive in Gaza.

Asked if he expected kidnapped American toddler Abigail Mor Idan to be in the first batch of hostages to be released, US President Joe Biden said: "I'm keeping my fingers crossed."

'A safe environment'

Palestinian prisoners held in Israeli jails will also be released on Friday, Qatari foreign ministry spokesperson Majed Al Ansari said, adding a list of names had been approved.

The agreement entailed a "complete ceasefire with no attacks from the air or the ground" and the skies clear of drones to "allow for the hostage release to happen in a safe environment", Ansari said.

Israel has published a list comprising the names of a total of 300 Palestinians who could be released, should the truce outlive the initial four-day period.

Among them are 33 women and 267 children and youths aged 19 and under. The list also includes 49 Hamas members.

The armed wing of Hamas agreed to the truce deal, which is also intended to provide aid to Gazans struggling to survive with shortages of food, water and fuel.

It said three Palestinian prisoners would be released for each one of the hostages.

Palestinian prisoners will be released from three jails in Israel and the occupied West Bank, then taken to the Ofer military camp on buses, an Israeli official told AFP on condition of anonymity, adding that they were expected to be freed in the evening.

Most are from the West Bank but five are from the Gaza Strip.

No end

Governments around the world have welcomed the agreement, with some expressing hope it will lead to a lasting end to the war.

"This cannot be just a pause before the massacre starts all over again," Riyad Mansour, Palestinian ambassador to the United Nations, told the Security Council.

Israeli officials, however, say the truce will be only temporary.

"We are not ending the war. We will continue until we are victorious," Israel's chief of staff, Lieutenant General Herzi Halevi, told troops he visited in Gaza.

Hours ahead of the pause, fighting raged.

Anti-rocket alarms sounded in an Israeli kibbutz near the Gaza border and explosions were heard and heavy grey clouds hovered over northern Gaza, much of which has been reduced to rubble.

Hamas health ministry official Munir al-Bursh told AFP that Israeli soldiers had raided the Indonesian Hospital in northern Gaza, though Israel did not immediately comment on any operation at the facility.

Israel has repeatedly said that hospitals have been used by Hamas to cloak underground command-and-control facilities — though Hamas and medical staff refute the claims.

In Gaza's largest refugee camp Jabalia, a Palestinian doctor said at least 27 people had been killed and 93 wounded Thursday in a UN-run school where thousands of displaced civilians were sheltering.

On Israel's northern border, Iran-backed militant group Hezbollah said it had stepped up its attacks from south Lebanon, where Israeli bombardments killed seven of its fighters, including members of an elite unit.

Since the Israel-Hamas war began, deadly exchanges across the border have killed 109 people in Lebanon, most of them Hezbollah fighters, and nine people in Israel, most of them soldiers, raising fears of a broader conflict.