GAZA CITY: Signs of renewed efforts for a Gaza ceasefire were evident on Friday as the death toll continued to climb after Israel shelled a UN shelter killing 15 Palestinians.

Israel's secretive security cabinet was expected to meet later in the day to discuss truce proposals passed to Israeli Prime Minister Benjamin Netanyahu by US Secretary of State John Kerry earlier in the week, Israeli media said.

Those reports came after an Israeli shell slammed into a UN facility sheltering displaced Gazans on Thursday, prompting UN chief Ban Ki-Moon to say he was “appalled” at the incident which “underscores the imperative for the killing to stop — and to stop now”.

Fresh Israeli fire early Friday pushed the overall Palestinian death toll in Gaza to over 800 Palestinians, emergency services spokesman Ashraf al-Qudra said.

He said that an air strike on a house in the southern Gaza town of Deir-el-Balah killed a woman of 26 and another aged 23 who was pregnant, as Israel pressed on with its 18-day campaign to stamp out Gaza rocket fire.

Two other people wounded earlier in shelling of the southern city of Khan Yunis died of their injuries, Qudra said, bringing the total number of Gazans killed in the Israeli campaign to 804.

Thursday's strike hit a UN school sheltering some of the 100,000 Palestinians driven from their homes in search of a safe haven after weeks of deadly fighting between Israeli troops and Hamas militants.

The shell crashed down in the middle of the courtyard where people were camped, leaving the ground covered in bloodstains, killing least 15 people and wounding more than 200.

Ban said: “Many have been killed — including women and children, as well as UN staff.“ Washington said it was “deeply saddened and concerned about the tragic incident”, without explicitly blaming its ally Israel for the shelling.

Palestinians protest to UN

The Palestinian ambassador to the United Nations wrote to the Security Council demanding action. “We demand an immediate, impartial and thorough investigation into this grave incident in order to establish accountability and bring the perpetrators of this crime to justice,” said the letter.

Kerry, in Cairo trying to negotiate a ceasefire, reached out to Hamas allies Turkey and Qatar on Thursday as he sought to further regional efforts to broker an end to the bloodshed.

His efforts are focused on a week-long humanitarian ceasefire, during which intensive negotiations will tackle the blockade of Gaza and other disputes, Western and Palestinian officials said.

Hamas earlier rejected an Egyptian proposal.

Its exiled leader Khaled Meshaal told the BBC in an interview Thursday that a truce must include a guaranteed end to Israel's eight-year blockade on the Gaza Strip.

“We want a ceasefire as soon as possible, that's parallel with the lifting of the siege of Gaza,” he said.

Most of Thursday's 98 Gaza victims were killed in and around Khuzaa, a flashpoint area east of Khan Yunis which has been the site of intensive fighting since Tuesday.

But the biggest single strike was at the school in the north, where the UN agency for Palestinian refugees (UNRWA) said it had been trying to coordinate with the army over the evacuation of civilians, without success.

“We've spent much of the day trying to negotiate or to coordinate a window so that civilians, including our staff, could leave,” spokesman Chris Gunness said.

“That was never granted... and the consequences of that appear to be tragic.“ Israeli army spokesman Lieutenant Colonel Peter Lerner suggested militants firing rockets near the school could have caused the deaths.

He also took issue with the claim that Israel had rejected a humanitarian truce around the school, saying it had implemented a four-hour window for evacuations.

Concern over civilian toll

The Gaza-based Palestinian Centre for Human Rights has said more than 80 percent of the casualties so far have been civilians, and a quarter of them children, triggering growing international alarm over the civilian body count.

“As this campaign goes on and the civilian casualties in Gaza mount, Western public opinion is becoming more and more concerned and less and less sympathetic to Israel,” warned British Foreign Secretary Philip Hammond.

UN humanitarian chief Valerie Amos expressed deep concern about the mounting civilian casualties, saying it was “almost impossible” for Palestinians to shelter from Israeli air strikes in the densely-populated territory.

Meanwhile, US airlines on Thursday lifted a two-day suspension of flights to Israel, but not all international airlines followed suit, with Germany's Lufthansa and Air France keeping their Tel Aviv flights grounded.

The ban was put in place on Tuesday after a rocket hit a house close to the runways.

A military spokeswoman said that Gaza militants had fired 2 rockets at southern Israel in the early hours of Friday, bringing the number of rockets and mortar shells from Gaza that hit Israel since July 8 to 1,850, with another 470 shot down by the Iron Dome defence system.

Late Thursday, a rocket fired by militants in the Sinai peninsula at the southern Israeli resort city Eilat was intercepted, the spokeswoman noted.

So far, 32 Israeli soldiers have died in the fighting. Hamas rocket attacks have killed two Israel civilians and a Thai migrant worker.

In the West Bank, thousands of Palestinians protesting the Gaza toll clashed with Israeli forces outside Jerusalem.One demonstrator was killed and over 150 injured by Israeli fire, five critically, Palestinian medical staff said.