By Bassam Masoud and Janis Laizans

GAZA/ISRAEL-GAZA BORDER (Reuters) -A temporary ceasefire between Israeli and Hamas forces took hold in the Gaza Strip on Friday, the first respite in 48 days of conflict that has devastated the Palestinian enclave, but both sides warned that the war was far from over.

No big bombings, artillery strikes or rocket attacks were reported although Hamas and Israel both accused each other of sporadic violations.

The ceasefire, which began at 7 a.m. (0500 GMT), involves the release later on Friday of 13 Israeli women and children held hostage by Hamas in exchange for Palestinian prisoners held in Israeli jails. Additional aid is to flow into Gaza, which has been gripped by a humanitarian crisis under weeks of Israeli bombardment that has killed thousands of Palestinians.

Reuters journalists saw Israeli tanks moving away from the Gaza Strip at the northern end, and aid trucks rolling in from Egypt at the southern end. There was no sound of Israeli air force activity above northern Gaza, nor any of the contrails typically left by Palestinian rocketfire.

In Khan Younis town in southern Gaza, housing thousands of families displaced from the north, streets filled with people venturing out of home and shelters.

"We are full of hope, optimism, and pride in our resistance. We are proud of our achievements, despite the pain this caused," resident Khaled Abu Anzah told Reuters.

Hamas confirmed that all hostilities from its forces would cease. But Abu Ubaida, spokesperson for Hamas' armed wing, later stressed that this was a "temporary truce".

In a video message, he called for an "escalation of the confrontation with (Israel) on all resistance fronts", including the Israeli-occupied West Bank.

The Israeli military also said fighting would resume soon.

"This will be a short pause, at the conclusion of which the war (and) fighting will continue with great might and will generate pressure for the return of more hostages," Israeli Defence Minister Yoav Gallant said, according to a Defence Ministry statement.

The Israeli military also told Palestinians not to try to return to homes in the northern part of Gaza, which it described as a "dangerous war zone".

Israel launched its assault on Gaza after Hamas fighters burst across the border fence into southern Israel on Oct. 7, killing 1,200 people and seizing about 240 hostages, according to Israeli tallies.

Since then, Israel has rained bombs on the Hamas-ruled enclave, killing some 14,000 Gazans, around 40% of them children, according to Palestinian health authorities.

Hundreds of thousands of Gaza's 2.3 million people have fled their homes to escape the violence as conditions grew ever more desperate, with food, drinking water, fuel and other basic supplies running short.

It is the bloodiest episode in the long-running Israeli-Palestinian conflict in decades. Israel's stated intention is to eradicate Hamas once and for all.

QUIET ON THE FRONT

Reuters observed the quiet after dawn from southern Israel, across the fence from the war zone in the northern part of the Gaza Strip, scene of intense ground combat since the start of the month. Dozens of Israeli military vehicles, including tanks, could be seen moving away from the Gaza Strip.

Arab media reported that Israeli forces were preventing residents from returning to their homes in Gaza's north. Soldiers opened fire in one incident, Al Jazeera said, but there was no indication that it resulted in casualties. There was no immediate comment from the Israeli military.

Sirens sounded in two Israeli villages outside the southern Gaza Strip, warning of possible incoming Palestinian rockets. An Israeli government spokesman said Hamas had fired rockets in violation of the truce but there were no immediate reports of damage.

Fighting had raged in the hours leading up to the truce, with officials inside the enclave saying a hospital in Gaza City was among the targets bombed.

The Indonesian Hospital was operating without light and filled with bedridden old people and children too weak to be moved, Gaza health officials said. Al-Jazeera quoted Mounir El Barsh, the Gaza health ministry director, as saying a patient, a wounded woman, was killed and three others injured.

There was no immediate comment from Israel on the reported incident.

Egypt said it was maintaining contact with Israel and Hamas to consolidate the truce and prevent violations.

WOMEN, CHILDREN HOSTAGES TO BE FREED

The first hostages, including elderly women, would be freed at 4 p.m. (1400 GMT), with the total number rising to 50 over the four days, Qatar's foreign ministry spokesperson Majed Al-Ansari said in Doha. All were seized in the initial Hamas assault on southern Israel.

The hostages were expected to be released to the Red Cross and an Egyptian security delegation that travelled to Gaza on Thursday, then brought out through Egypt for transfer to Israel, Egyptian security sources said.

Israel will release 39 Palestinians prisoners, among them 24 women and 15 teenagers, in the occupied West Bank in exchange for the 13 hostages due to be freed from the Gaza Strip by Hamas, a Palestinian official said.

"We all hope that this truce will lead to a chance to start a wider work to achieve a permanent truce," he said.

Under the agreement, desperately-needed aid began to be delivered to Gaza. By mid-morning, 60 trucks carrying aid had crossed from Egypt at the Rafah border point, according to Gaza border authorities.

Two of the first trucks to enter sported banners that said, "Together for Humanity." Another said: "For our brothers in Gaza."

Egypt has said 130,000 litres of diesel and four trucks of gas will be delivered daily to Gaza and that 200 trucks of aid would enter Gaza daily.

Israel's COGAT agency, which liaises with the Palestinians on civilian affairs, said four tanks of fuel and four tanks of cooking gas were transferred from Egypt to U.N. humanitarian groups in southern Gaza via Rafah.

Egyptian authorities said some Palestinians stuck in Egypt were starting to return to Gaza Strip through the Rafah crossing.

People in southern Gaza who had evacuated homes in the early days of the war to shelters deeper west, started to go to their home areas to check on their houses.

(Reporting by Reuters bureauWriting by Angus MacSwanEditing by Peter Graff)