Aid agencies have been warning of a severe humanitarian crisis
Israel has halted military operations in Gaza for three hours in the first of what it says will be a daily ceasefire.
An Israeli spokesman said it would allow Gazans to "get medical attention, get supplies... whatever they need".
Correspondents say it is unclear if the suspension covers all of Gaza. Fighting resumed shortly after 1400GMT, eyewitnesses said.
Israel's move came as pressure built on it and the Palestinian militant group Hamas to accept a ceasefire deal.
The plan, backed by the UN and the US and proposed by Egypt and France, calls for an immediate ceasefire.
Israel's security cabinet is meeting to consider the deal, but ministers are also expected to discuss expanding operations in Gaza.
In a statement released on Wednesday, France's President Nicolas Sarkozy said he welcomed what he described as "the acceptance by Israel and the Palestinian Authority" of the French-Egyptian ceasefire plan.
The statement did not mention Hamas. A senior Hamas official told the BBC that there were "positive signs but no agreement yet".
Israel said it "welcomes" the initiative but that talks were continuing on the details of the proposal.
An official told the BBC: "We are still having a dialogue. We have agreement on the principles. The challenge now is to get the details to match the principles."
Israel was not sure how long the diplomatic process would take and would need a working arms embargo on Hamas, the official said.
Israel's military said the three-hour pause in operations to create "humanitarian corridors" for supplies and fuel would happen every day.
A Hamas spokesman told Al Arabiya television that the group would not launch any missiles at Israeli targets during the lull.
Israel has been criticised by aid agencies who have warned of a mounting humanitarian crisis for the 1.5 million Palestinians in Gaza, who are unable to escape from the conflict because of Israel's blockade.
However Christopher Gunness, a spokesman for the UN relief agency Unrwa, said the move did not go far enough.
"When you are trying to feed 750,000 people a day in Gaza as we are, you need a permanent ceasefire. You can't do that in a three-hour window," he said.
The World Bank also warned on Wednesday of a looming public health crisis in Gaza because of damage to its sewage system and a shortage of clean drinking water.
It urged Israel to allow the entry of parts, fuel and staff to the sewage complex in order to prevent the system breaching its walls and drowning up to 10,000 people.
Israel's decision to facilitate "humanitarian corridors" follows one of the deadliest days since the offensive began last month, with more than 130 people killed on Tuesday.
Overnight, Israeli forces launched 40 fresh air strikes in Gaza, while Israeli media reports say nine rockets were fired into southern Israel from Gaza early on Wednesday.
Little official detail has been given about the French-Egyptian ceasefire proposal, but diplomats say it centres around measures to halt weapons smuggling from Egypt into Gaza, coupled with moves to ease the blockade.
The aftermath of a rocket attack on Ashkelon, southern Israel
A Palestinian official said Gaza's Hamas rulers, who want an end to Israel's blockade of the enclave, were debating the proposal, the Reuters news agency reported.
Israel wants to stop rocket attacks on southern Israel and to stop Hamas smuggling weapons into Gaza via Egypt, while Hamas says any ceasefire deal must include an end to Israel's blockade of the Gaza Strip.
More than 600 Palestinians are now believed to have been killed since Israel began its offensive on 27 December.
Palestinian health ministry officials say at least 195 children were among those killed.
An Israeli attack on Tuesday on a UN-run school building, being used to shelter people who had fled their homes, killed 40 people, UN officials say.
The Israeli military said its soldiers had come under mortar fire from Hamas militants inside the school.
However, Unrwa's Christopher Gunness said the agency was "99.9% certain" that there were no militants or militant activity in the school compound, and called for an independent investigation into the incident.
A spokesman for Hamas denied there had been any hostile fire coming from the school.
Since the start of its military operation in Gaza, Israel has lost seven soldiers on the ground. Four people within Israel have been killed by rockets.
At least five hit southern Israel on Tuesday, one of them injuring a baby.
Support for truce
US Secretary of State Condoleezza Rice welcomed the French-Egyptian plan, saying the US was "pleased by and wish[es] to commend... that initiative".
Israel's ambassador to the UN, Gabriela Shalev, did not say whether Israel would accept the proposal but said it would take it "very, very seriously".
The contours of a possible diplomatic agreement are in place, the BBC's Laura Trevelyan reports from the UN.
However, if Israel continues to control the flow of humanitarian aid into Gaza and can choose to stop it at any time this seems unlikely to command the support of Hamas, our correspondent notes.
Casualty claims in Gaza cannot be independently verified. Israel is refusing to let international journalists into Gaza, despite a supreme court ruling to allow a limited number of reporters to enter the territory.
Update: In February 2009, the United Nations said that a clerical error had led it to report that Israeli mortars had struck a UN-run school in Jabaliya, Gaza, on 6 January killing about 40 people. Maxwell Gaylord, the UN humanitarian co-ordinator in Jerusalem, said that the Israeli Defense Force mortars fell in the street near the compound, and not on the compound itself. He said that the UN "would like to clarify that the shelling and all of the fatalities took place outside and not inside the school".
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