Israel agreed to a UN request to halt its bombardment of Gaza for five hours on humanitarian grounds, after its naval strikes killed four children on a beach Wednesday.
The punishing strikes aimed at halting cross-border rocket fire by Hamas militants had resumed after Egyptian-brokered truce efforts collapsed Tuesday.
Israel's campaign, now in its ninth day, has killed 220 Palestinians so far, with a Gaza-based human rights group saying over 80 percent of them were civilians.
In the same period, militants have fired more than 1,200 rockets at Israel. They claimed their first Israeli life on Tuesday.
Hamas rejected the Egyptian truce efforts, saying it had not been included in the discussions.
The Israeli army announced it would halt its bombardment of Gaza between 10:00 am and 3:00 pm (0700 to 1200 GMT) Thursday, following a UN request for a humanitarian truce.
UN Special Coordinator for the Middle East peace process Robert Serry earlier told Israel's Channel Two television, that he had asked the military for a "humanitarian pause" in its Gaza offensive and that, if it agreed, he would ask Gaza militants to follow suit.
Hamas said it was considering the request.
"Hamas has been informed about the UN proposal for a truce of several hours tomorrow," Hamas spokesman Sami Abu Zuhri told AFP.
"The proposal is being studied and when a decision has been taken, it will be announced officially in a statement."
As part of the peace initiative, a Hamas official met Egyptian leaders while Palestinian president Mahmud Abbas arrived in Cairo to join the diplomatic efforts.
In addition to the four killed children, several people were also wounded in an apparent Israeli naval bombardment of a beach in Gaza City, medics said.
The first strike hit at around 1300 GMT, prompting terrified children and adults on the beach to scatter. A second and third struck as they ran, setting fire to huts on the beach.
The strikes appeared to be the result of shelling by the Israeli navy against an area with small shacks used by fishermen.
Several children ran inside a hotel where at least three had shrapnel injuries.
The four bodies were later taken to Abu Hasira mosque, near where the boys had died.
The boys, all from the Bakr family, were laid out, wrapped in the yellow flags of the Fatah party, in front of mourners.
Several hours after the strikes, the Israeli military described the deaths as "tragic" and said it was investigating the incident.
"Based on preliminary results, the target of this strike was Hamas terrorist operatives," the military said in a statement.
"The reported civilian casualties from this strike are a tragic outcome."
- Nowhere to run to -
The Israeli military dropped flyers and sent text messages warning 100,000 people in northeastern Gaza to evacuate their homes ahead of an air campaign targeting "terror sites and operatives" in Zeitun and Shejaiya, two flashpoint districts east of Gaza City.
An identical message was sent to Beit Lahiya in the north, echoing a similar army warning on Sunday, when more than 17,000 residents of the north fled for their lives, most seeking refuge in UN-run schools.
But for patients at Al-Wafa hospital in Shejaiya, the warning simply provoked even more fear.
"We cannot leave our patients, they are helpless," director Basman Alashi told AFP, saying most of them were completely incapacitated.
"There is no place safe in Gaza. If a hospital is not safe, where is?" he said as the sound of nearby shelling rattled the windows.
Limited numbers were seen heeding the Israeli warnings. Children picked up many of the flyers and played with them.
"Where should we go?" asked Faisal Hassan, a father of five who lives in Zeitun.
Hamas dismissed the warning as a scare tactic, telling residents there was "no need to worry."
- Hamas in fresh Cairo talks -
Prime Minister Benjamin Netanyahu vowed on Tuesday to step up the military campaign after Hamas dismissed an Egyptian ceasefire proposal, firing scores of rockets over the border despite the army holding its fire for six hours.
"This would have been better resolved diplomatically... but Hamas leaves us no choice but to expand and intensify the campaign against it," he said.
His security cabinet authorised the call-up of another 8,000 reservists, media reports said, joining 43,000 reserve troops who have already been mobilised.
Azzam al-Ahmad, a senior member of Abbas's Fatah movement, said a Hamas official was in Cairo to hold talks with Egyptian officials.
Ahmad expressed hope that the talks in Cairo would "crystallise a definite formula for an Egyptian initiative" or clarify its plan, which had proposed an end to hostilities from 0600 GMT Tuesday.
In a joint news conference with Netanyahu in Jerusalem, visiting Italian Foreign Minister Federica Mogherini said she hoped that Hamas would "revise its position and accept the proposal in the coming hours or days."
Abbas himself later arrived in Cairo to join the diplomatic efforts and was slated to travel to Ankara on Thursday in search of regional support for an immediate end to the fighting.
Also in Cairo, Middle East peace Quartet envoy Tony Blair met Egyptian President Abdel Fattah al-Sisi and Foreign Minister Sameh Shoukri.
Egypt's initiative was designed "to allow all the issues that are at the heart of this problem... to be dealt with in a thorough and proper way," Blair said.
Separately, US Secretary of State John Kerry said Washington was doing "everything in our power" to end the bloodshed in Gaza.
"Our concern is to have a legitimate ceasefire and see if we can find a way to stop the conflict and killing so we can get to the real issues that are underlying it," he told reporters, adding that he has been speaking to Netanyahu and Arab officials.