Images of the bloodshed in Gaza, which has claimed more than 1,800 Palestinian lives and 67 in Israel, have sent tensions soaring across the region, earning the Jewish state strong criticism for the soaring numbers of civilian casualties.
"How many more deaths will it take to stop what must be called the carnage in Gaza?" asked French foreign minister Laurent Fabius.
But Israeli Prime Minister Benjamin Netanyahu said there would be no end without first securing a long-term period of calm for his people.
"The campaign in Gaza is continuing," he said at the end of a seven-hour humanitarian lull which saw violence subside in the battered Palestinian enclave.
"This operation will only end when quiet and security is established for the citizens of Israel for a prolonged period."
Violence also erupted in Jerusalem, with police saying they had foiled a "terror attack" after a Palestinian rammed an earthmover into a bus, killing one and wounding five before being shot dead himself.
Shortly afterwards, a soldier was shot and badly wounded near a bus stop not far from the site of the earlier attack by a gunman who fled, with police combing the area to find him.
Meanwhile on the ground, Israel troops, which had begun withdrawing from besieged enclave at the weekend, largely held their fire in Gaza during a unilateral seven-hour truce, which began at 0700 GMT.
The humanitarian window got off to a shaky start with an air strike levelling a house in a beachfront refugee camp in Gaza City, killing three people, among them a nine-year-old girl, the emergency services said.
The strike cause the house to pancake, leaving a huge pile of rubble strewn with twisted metal rods and broken glass and only a very narrow gap for rescuers to get inside.
"There is no truce. How could there be a truce," raged Ayman Mahmud, who lives in the neighbourhood.
"They are liars! They don't even respect their own commitments!"
Hamas did not observe the truce, firing 42 rockets over the border during the pause, 24 of which hit Israel and another one which was shot down, the army said.
And Gaza medics said they retrieved 32 bodies from the rubble.
A military spokesman later said troops were resuming their operations, "including air strikes" but said they were also continuing to redeploy within Gaza while others were pulling out.
Truce follows pressure
The unilateral truce was announced as international outrage grew over an Israeli strike near a UN school on Sunday that killed 10 people, among them refugees who had been seeking shelter.
It was the third such strike in 10 days.
With UN figures indicating most of the 1,865 people killed in Gaza so far were civilians, the world has stepped up its demands for an end to the bloodshed.
In Paris, France's top diplomat, an increasingly vocal critic of the war, demanded the world impose a political solution to end "the carnage".
"Israel's right to security is total, but this right does not justify the killing of children and the slaughter of civilians," he said, with French President Francois Hollande urging an end to the "massacres" in Gaza.
Their remarks came a day after the UN denounced a fresh strike on one of its schools which was sheltering 3,000 refugees as "a moral outrage and a criminal act", and the United States said it was "appalled".
Israel acknowledged targeting three militants near the school and said it was investigating the consequences of the strike.
Russia's top diplomat Sergei Lavrov also added his voice to growing calls for an agreement to end the violence, his ministry said Monday.
In Cairo, truce talks between a Palestinian delegation and Egyptian officials were ongoing.
Israel turned down an invitation to attend, with Hamas accusing the Jewish state of attempting to scuttle the talks in a bid to avoid blame for its "escalating massacres" in Gaza.
The Palestinians want Israel withdraw all troops from Gaza, end its eight-year blockade of the enclave and open border crossings.
Bloodshed in Jerusalem
In Jerusalem, meanwhile, one Israeli was killed and five hurt when a Palestinian rammed an earthmover into a bus, turning it over before the driver was shot dead by police, according to Israeli officials.
Shortly afterwards, an Israeli soldier was shot and seriously wounded near a bus stop not far from the site of the earlier attack, with police combing the area for his attacker.
Police said the attack on the bus was a "terrorist attack," saying the driver was a Palestinian from annexed east Jerusalem.
An crowd of angry Israelis gathered at the scene, chanting "Death to Arabs" and dozens of people could be seen attacking a nearby bus filled with Arab workers.