Israeli fire has pushed the Palestinian death toll in Gaza to above 800, as Washington pressed Israel and Hamas to agree to a week-long humanitarian ceasefire and thrash out a durable truce.

In the West Bank, Palestinian factions declared a “Day of Rage” after a night of clashes over Israel’s Gaza offensive, with one Palestinian killed.

Among the dead in an air strike on Friday were two women, one of them pregnant, adding to a spiralling toll of Palestinian civilian casualties from Israel’s military operation, now in its 18th day, aimed at halting militant rocket fire.

On Thursday, Israeli shelling of a UN facility sheltering displaced Gazans killed at least 15 civilians, drawing widespread international condemnation.

UN chief Ban Ki-moon said he was “appalled” at the incident which “underscores the imperative for the killing to stop – and to stop now”.

With intense international pressure on both sides to cease fire, Israel’s security cabinet was to meet on Friday to discuss a truce proposal passed to Prime Minister Benjamin Netanyahu by US Secretary of State John Kerry, media reported.

It proposes an initial week-long humanitarian ceasefire that would allow Hamas, the de facto power in Gaza, to save face after having rejected an Egyptian initiative last week that proposed a lasting truce first and negotiations later.

Turkish Foreign Minister Ahmet Davutoglu flew to Qatar on Friday to help efforts for a ceasefire after Kerry on Thursday reached out to Hamas allies Ankara and Doha to push for a ceasefire.

According to Western and Palestinian officials, once a humanitarian lull takes hold, delegations from Israel and Hamas would arrive in Cairo – which has mediated past conflicts between the two – for indirect talks that could lead to a lasting truce.

However, Israel’s security cabinet looked unlikely to want a ceasefire, commentators said.

“Some fear that the security cabinet will go into a state of euphoria and attempt to accomplish a new goal, which was not presented before, such as toppling Hamas,” Yediot Aharonot wrote in an editorial.

Hamas’s exiled Doha-based leader Khaled Meshaal, however, told the BBC that any truce must include a guaranteed end to Israel’s eight-year blockade of Gaza.

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

The latest truce efforts came on the last Friday of Ramadan, as Israeli braced for West Bank and east Jerusalem unrest after Palestinian factions declared a “Day of Rage” and Israeli police restricted entry to the Al Aqsa compound to men aged 50 and above.

An attack on a house in central Gaza killed two women, one of whom was pregnant, emergency services spokesman Ashraf al-Qudra said.

Friday’s Gaza violence brought the death toll to 815 Palestinians, he said.

Rights groups say around 80 per cent of the casualties so far have been civilians, a quarter of them children, triggering growing international alarm.

UN humanitarian chief Valerie Amos warned it was “almost impossible” for Palestinians to shelter from Israeli air strikes in the densely populated territory.

Thirty-two Israeli soldiers have been killed, and Hamas rocket attacks have killed two Israeli civilians and a Thai worker.