Israel and Hamas militants have agreed to a United Nations request for a temporary cease-fire in Gaza on Thursday.
The truce will last five hours to give Palestinian civilians a chance to restock supplies, repair damaged buildings, and get medical care.
But Israel warns it will react if militants fire rockets during the truce.
Palestinian officials say the death toll since Israel began its offensive last week rose to 213 Wednesday. Four children were killed by an Israeli airstrike while playing on a beach near Gaza City.
Television cameras captured the scene as the shells hit the beach and the youngsters tried to run away.
Israeli officials call the deaths "tragic" and say they are investigating. But they say Hamas militants deliberately fire rockets from areas crowded with civilians, using them as human shields. They accuse Hamas of war crimes.
Prime Minister Benjamin Netanyahu says Israel will continue to do what it has to to protect its citizens from attacks by Hamas and other militants.
At the White House Wednesday, President Obama said the U.S. will use all its diplomatic resources and relationships to bring the conflict between Israel and Hamas to an end.
An Egyptian-backed cease-fire proposal collapsed after only a few hours Tuesday when Hamas militants fired rockets into Israel, forcing the Israeli army to retaliate.
U.S. Secretary of State John Kerry said a legitimate cease-fire would help diplomats get to what he called the "real issues" beneath the fighting.
Palestinians are demanding that Israel lift a long-standing blockade of the Gaza Strip, which is governed by Hamas. Israel regards Hamas as a terrorist group. It is angered that the moderate Fatah wing in the West Bank formed a unity government with Hamas.
Goal of military operation
Israeli military spokesman Lieutenant Colonel Peter Lerner said the strikes are part of operations to disrupt the group's terrorist activities.
"The line between political and terrorist activists is extremely vague as far as Hamas is concerned, and the people we struck is the leadership who are involved in terrorist activities, involved in coordinating and leading and instructing these types of activities,” Lerner said.
Israel began what is called Operation Protective Edge nine days ago as a counter to Hamas firing rockets into Israel.
Lerner said 70 rockets were fired at Israel on Wednesday, 25 of which were intercepted by the Iron Dome missile defense system.
The human cost
By far, however, most casualties have been on the Palestinian side.
A rehabilitation hospital in Gaza was also damaged in Wednesday's strikes.
The director of the Wafa clinic, Basman Alashi, told VOA this was the sixth time the hospital has been hit since the conflict began last week.
"This is not a strategic building, this is not a military building and we are not here yesterday or a month ago or a year ago. We are here since 1996,” Alashi said.
Most of the patients at the hospital are comatose and have been moved to the first floor hallway for safety. Alashi said staff members intend to stay in place to care for them.
Lerner denied Israel targeted the hospital.
"I think specifically what happened last night is we phoned them up and we warned them that there is a rocket launcher adjacent to the building that we suggest they vacate the building because of this rocket launcher,” Lerner said.
“They said 'No,' and we recommended that they stay away from the windows because we intend to strike the rocket launcher that is on the immediate premises,” he added.
Alongside the airstrikes, Israel also told tens of thousands of residents of the northern town of Beit Lahiya and the Zeitoun and Shijaiyah neighborhoods of Gaza City, all near the border with Israel, to evacuate their homes by 8 a.m. Wednesday. The warnings were delivered in automated phone calls, text messages and leaflets dropped from planes.
The Israeli military said in its message that large numbers of rockets were launched from these areas and that Israel plans to bomb these locations.
“Whoever disregards these instructions and fails to evacuate immediately, endangers their own lives, as well as those of their families,” the message said.
Hamas officials told people to ignore the warnings, saying Israel was using "psychological warfare."
Meanwhile, Palestinian President Mahmoud Abbas is due in Cairo to meet with Egyptian President Abdel-Fattah el-Sissi to discuss an Egyptian-backed cease-fire deal.
Israel had accepted the truce offer Tuesday, which included an end to the fighting and further talks in Egypt, but Hamas objected to the terms.
The group's leaders had also demanded additional conditions, including the easing of an Israeli blockade on Gaza.
At a news conference Wednesday, Israeli Prime Minister Benjamin Netanyahu said Hamas militants in Gaza are committing war crimes by directly targeting millions of Israeli civilians with rocket fire and using their own civilians as human shields. He also said the Hamas organization has "shut the door to a diplomatic solution" and bears the responsibility for the continuation of violence.
Since the conflict began, relations have deteriorated between Abbas' Fattah movement, which governs the West Bank, and Hamas, despite a reconciliation agreement signed between the two last month.
Also Wednesday, U.S. Secretary of State John Kerry said he was conversing with leaders in the Middle East to forge a ceasefire in Gaza.
“Our concern is to have a legitimate ceasefire and see if we can find a way to stop the conflict, killing, so we can get to the real issues that are underlying it. And, we are doing everything in our power," Kerry said.
Kerry said he spoke with Israel’s Netanyahu and Egyptian Foreign Minister Sameh Shukri, adding that he will continue his diplomatic discussions.
Some information for this report provided by Reuters and AP.
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