An Israeli air strike killed at least 10 people and wounded about 30 others on Sunday in a UN-run school in the southern Gaza Strip, witnesses and medics said, as dozens died in renewed Israeli shelling of the enclave.
The Israeli military declined immediate comment on the attack, the second to hit a school in less than a week. A missile launched by an aircraft struck the entrance to the school in the town of Rafah, the witnesses and medics said.
Hundreds of Palestinians in the area, where the Israeli military has been battling militants, had been sheltering in the facility.
Last Wednesday, at least 15 Palestinians who sought refuge in a UN-run school in Jabalya refugee camp were killed during fighting, and the UN said it appeared that Israeli artillery had hit the building. The Israeli military said gunmen had fired mortar bombs from near the school and it shot back in response.
Earlier on Sunday, Israeli shelling killed at least 30 people in Gaza, a day after Prime Minister Benjamin Netanyahu vowed to keep up pressure on Hamas even after the army completes its core mission of destroying a tunnel network that extends into Israel.
Read: Hamas delegation arrives in Cairo for Gaza talks
An Israeli soldier carries a shell at a mobile artillery unit while it fires towards the Gaza Strip. (Reuters photo)
In Cairo, efforts to find a new truce were due to resume on Sunday.
A delegation from Palestinian militant groups Hamas and Islamic Jihad arrived in the Egyptian capital, but a quick breakthrough seemed unlikely in the absence of Israeli representatives.
After accusing Hamas of breaching a US- and UN-brokered ceasefire on Friday, Israel said it would not send envoys as scheduled.
In Gaza, Israel intensified attacks in the area of Rafah along the border with Egypt, where 23-year-old officer Hadar Goldin was feared captured there on Friday shortly after what was to have been a 72-hour truce began.
The military later said Goldin, who was dragged by militants into a tunnel after two of his comrades were killed by a suicide bomber, had also died in action.
"The findings on the ground, the items that we found led us to the conclusion that he was killed in the initial attack," said lieutenant colonel Peter Lerner, a military spokesperson.
Lerner said ground forces were being redeployed in the Gaza Strip, though he gave no details of their new positions, and added that residents from a number of evacuated Palestinian neighbourhoods had been told by the military they could return.
Read: Israel declares missing soldier dead, Gaza toll rises
More than 30 tunnels and dozens of access shafts have been unearthed and were being blown up.
"We have proceeded with the mission in order to eliminate those (tunnels) that we have found and we expect to complete that within a short period of time, probably within the next 24 hours or so," he said.
Israel began its air and naval offensive against Gaza on July 8 following a surge of cross-border rocket salvoes by Hamas and other guerrillas, later escalating the operation into ground incursions.
The fighting on Sunday pushed the Gaza death toll given by Palestinian officials to 1,726, most of them civilians. Israel has confirmed that 64 soldiers have died in combat, while Palestinian rockets have also killed three civilians in Israel.
At least 30 Palestinians in Rafah were killed by Israeli fire on Sunday, including nine from the same family, hospital officials said.
Palestinians return to the heavily bombed Gaza City neighborhood of Shijaiyah, close to the Israeli border. (AP photo)
The talks in Cairo, without Israeli participation, were unlikely to produce any breakthrough, as Israel and Hamas' positions remain far apart.
Israel says it wants Gaza demilitarised under any long-term arrangement. Hamas, sworn to Israel's destruction, demands Israel withdraw its troops and a lifting of Israeli and Egyptian blockades that have choked Gaza's economy.
Israeli justice minister Tzipi Livni, a member of Netanyahu's decision-making security cabinet, said any agreement on the issue was still far off.
"You want to talk about lifting the blockade? Not with us, and not now," she told the news website Ynet.
Read: Gaza attack – The outrage of the beautiful people
Crowded Gazan towns close to the Israeli border have seen destructive clashes and the flight of tens of thousands of Palestinians as tanks and troops swept in to confront dug-in guerrillas.
The Palestinian Centre for Human Rights said 520,000 people had been displaced by the fighting - more than a quarter of Gaza's population.
Britain believes the situation in the Gaza Strip has become intolerable, foreign secretary Philip Hammond. He told the Daily Telegraph he was receiving thousands of emails from Britons "deeply disturbed" at events in Gaza.