Israeli warplanes pummelled Gaza with 40 air strikes that killed five Palestinians on Saturday as militants hit back with 14 rocket attacks, leaving international mediators scrambling to rescue ceasefire talks.
Gaza emergency services said at least five men were killed in Israeli raids -- two travelling by motorcycle through Al-Maghazi refugee camp and three pulled from the rubble of Al-Qassam mosque in the middle of the enclave.
The Palestinian interior ministry said Israeli jets destroyed three mosques. At least two of them were considered close to Hamas.
Only the minaret was left standing at the huge Al-Qassam mosque in Nuseirat, an AFP photographer said.
Resident Ibrahim Taweel said the Israeli military telephoned him at 3am, warning him to evacuate his nearby home five minutes before the mosque was attacked.
"I couldn't tell all my neighbours, so I evacuated myself and my neighbour and after five minutes an F-16 fired one rocket and after that a bigger rocket destroyed the mosque," he said.
The army said Palestinian militants fired 14 rockets into Israel, bringing to 52 the number of projectiles launched at the Jewish state since a 72-hour truce ended on Friday.
One civilian and a soldier were wounded on Friday, but no injuries or damage in Israel were reported on Saturday.
Israel said it had carried out more than 100 strikes in Gaza since Friday, 40 of them since midnight.
Palestinian medics say those strikes have killed 10 people.
- Clashes in West Bank -
In the occupied West Bank, fresh clashes broke out after the funerals of two Palestinian men shot dead by Israeli troops during protests against the Gaza operation on Friday, witnesses said.
Palestinian youths threw stones and Israeli troops responded with tear gas and stun grenades.
The 72-hour truce collapsed after mediators in Cairo failed to extend a ceasefire when it expired on Friday morning as Israel accused Hamas of breaching the quiet with pre-dawn rocket attacks.
The conflict has now killed at least 1,900 Palestinians and 67 people on the Israeli side, almost all soldiers, since July 8.
The United Nations says at least 1,354 of the Palestinian dead were civilians, including 447 children.
Hamas, whom Israel brands a terror organisation and which de facto controls Gaza, vowed no concessions.
"The occupier's intransigence will get it nowhere and we will make no concessions on the demands of our people," spokesman Fawzy Barhum said in a statement.
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The lifting of Israel's land and sea blockade, imposed in 2006 after Hamas captured an Israeli soldier, has been a key demand of Hamas and the Palestinian Authority in Cairo talks.
A Palestinian official said on condition of anonymity Egypt and the Palestinians had reached a draft agreement for submission to Israel on Saturday.
It would see Egypt and the Palestinian Authority take control of the Rafah border crossing into Egypt, in which Hamas would essentially activate a unity deal signed with the PA in April.
Negotiations on the sea port, demanded by Hamas, would then be delayed and entrusted to the Palestinian Authority, with whom Israel is prepared to deal.
Israel waged the conflict to destroy Hamas's arsenal of rockets and its network of attack tunnels.
- Hopes of new truce -
But combat has not resumed at the same fierce intensity, feeding hopes of a new truce bring agreed.
"Our hope is that the parties will agree to an extension of the ceasefire in the coming hours," US State Department spokeswoman Marie Harf said.
Acting US Middle East peace envoy Frank Lowenstein, in Cairo for some days, "is still trying to help the parties get a permanent ceasefire," a US embassy official said.
President Barack Obama told The New York Times in an interview published Saturday that there were limits to US influence on both sides to reach a solution to the decades old Israeli-Palestinian conflict.
Israeli Prime Minister Benjamin Netanyahu had a strong support base and Palestinian president Mahmud Abbas was weak domestically, he said.
"If he (Netanyahu) doesn't feel some internal pressure, then it's hard to see him being able to make some very difficult compromises, including taking on the settler movement," Obama was quoted as saying.
"In some ways, Bibi is too strong (and) in some ways Abu Mazen is too weak to bring them together."
Chris Gunness, spokesman for the UN agency for Palestinian refugees (UNRWA), called for the Gaza blockade to end so enable reconstruction can begin.
"Huge swathes of Gaza have been levelled. We cannot rebuild it with our hands tied behind our backs," he said. "The blockade must end... All those directly and indirectly responsible for the carnage and destruction must engage," he added.
At least 65,000 people have had their homes destroyed, and UNRWA said 222,000 people are still sheltering in 89 UN schools.
US-based Human Rights Watch said the knocking out of Gaza's only electrical power plant, by apparent Israeli shellfire, has worsened the humanitarian crisis.