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The Israeli military pressed ahead with its aggressive offensive against Palestinian rocket operations Sunday, intercepting at least two rockets fired toward Tel Aviv with the country's new `Iron Dome' missile defense system.

Police spokesman Micky Rosenfeld said two rockets were fired Sunday. It was impossible to immediately reconcile the reports.

Thousands of Israeli troops are massed near the Gaza border, meanwhile, awaiting an order to invade should Israeli leaders decide to widen the operation.

"The Israeli military is prepared to significantly expand the operation," Prime Minister Benjamin Netanyahu declared at the start of the weekly Cabinet meeting.

Israel expanded its airstrike campaign on rockets in the Gaza Strip over the weekend, striking a Hamas government compound and a Cabinet building where Gaza Prime Minister Ismail Haniyeh met with Egypt's prime minister last week.

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The 'Iron Dome' battery system intercepted an incoming projectile Saturday that was also bound for Tel Aviv, Israel's commercial capital.

President Obama says Israel has a right to defend itself from missiles being aimed at the country by militants in the Gaza Strip.

Obama says "no country on earth would tolerate missiles raining down" on its people and says any effort to resolve the conflict in Gaza "starts with no missiles being fired into Israel's territory."

A top aide to President Barack Obama told reporters traveling with the president to Asia on Air Force One that the U.S. and Israel both want an end to the rocket fire that's coming from the Hamas-ruled Gaza Strip.

Deputy national security adviser Ben Rhodes said Obama and Israeli Prime Minister Benjamin Netanyahu agree that "de-escalation is preferred," provided that Hamas stops firing into Israel.

Obama has spoken with the leaders of Egypt and Turkey, too.

Rhodes said they "have the ability to play a constructive role in engaging Hamas" and encouraging a de-escalation of the attacks.

In Egypt, President Mohammed Morsi hosted leaders from Hamas and two key allies, Qatar and Turkey, to seek a way to end the fighting.

"There are discussions about the ways to bring a cease-fire soon, but there are no guarantees until now," Morsi said at a news conference Saturday. He said he was working with Turkey, Arab countries, the U.S., Russia and western European countries to halt the fighting.

On Sunday, five Palestinian civilians were killed in airstrikes, including four children ranging in age from one to seven, according to Ashraf al-Kidra, a Gaza health official. Two of the children, a 3-year-old girl and a 5-year-old boy, were from the same family and were killed by an airstrike on their home in the Jebaliya refugee camp.

The deaths bring to 51 the number of Palestinians killed since the operation began. One third of the dead were civilians, and more than 400 civilians have been wounded, al-Kidra said. On the Israeli side, three civilians have been killed and more than 50 wounded by rocket fire.

Israel's military spokesman warned that Israel would go after Hamas commanders Sunday, in addition to rocket squads, in "more targeted, more surgical and more deadly" attacks.

Brig. Gen. Yoav Mordechai made the threat as Israel found itself at the crossroads of whether to launch a ground invasion or pursue Egyptian-led truce efforts. Israel has said it is not prepared to enter into a truce without guarantees the rocket fire won't resume.

Early Sunday, the military carried out dozens of attacks on rocket-launching sites, a major training base and the attacks on the two media centers. Israeli gunboats also fired on militant sites on the Gaza shore line, the military said without elaborating.

Gaza militants have widened their rocket range, compared to previous conflicts, firing rockets toward Tel Aviv and Jerusalem and putting 3.5 million Israelis, or nearly half the country's population, within reach.

Mordechai, the Israeli military spokesman, told Army Radio that despite truce efforts, the military has been ordered to intensify its attacks, following a late-night meeting led by Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak.

"I imagine in the next few hours, we will see ongoing targeted attacks on gunmen and Hamas commanders," Mordechai said. "More targeted, more surgical and more deadly."

Israel launched its military campaign Nov. 14 after days of heavy rocket fire from Gaza and has carried out hundreds of airstrikes since, the military said.

Gaza militants, undaunted by the heavy damage the air attacks have inflicted, have unleashed more than 500 rockets against the Jewish state, including new, longer-range weapons turned for the first time this week against Jerusalem and Israel's Tel Aviv heartland.

Two rockets landed in open fields outside of Jerusalem after air raid sirens sounded in the city last week, sending Israelis running for cover. The strike marked the first time the holy city has been targeted by rockets fired by Gaza militants. There were no immediate reports of damage or causalities.

Israeli media say the rocket fell north of Jerusalem, as witnesses say they saw a stream of smoke in Mevasseret Zion, a suburb.

Israeli police spokeswoman Micky Rosenfeld said the rocket landed in an open area near Gush Ezion, a collection of Jewish settlements in the West Bank southeast of the city.

The attack marks a major escalation, both for its symbolism and its distance from the Palestinian territory. Jerusalem had been thought to be beyond the range of Gaza rocket squads.

"We are sending a short and simple message: There is no security for any Zionist on any single inch of Palestine and we plan more surprises," Abu Obeida, a spokesman for the Hamas militant wing said.

An Israeli ground offensive could be costly to both sides. In the last Gaza war, Israel devastated large areas of the territory, setting back Hamas' fighting capabilities but also paying the price of increasing diplomatic isolation because of a civilian death toll numbering in the hundreds.

The current round of fighting is reminiscent of the first days of that three-week offensive against Hamas. Israel also caught Hamas off-guard then with a barrage of missile strikes and threatened to follow up with a ground offensive.

Israel has improved its missile defense systems, but is facing a more heavily armed Hamas. Israel estimates militants possess 12,000 rockets, including more sophisticated weapons from Iran and from Libyan stockpiles plundered after the fall of Muammar Qaddafi's regime there last year.

Netanyahu, who has clashed even with his allies over the deadlock in Mideast peace efforts, appears to have less diplomatic leeway than his predecessor, Ehud Olmert, making a lengthy military offensive harder to sustain.

What's more, regional alignments have changed dramatically since the last Gaza war. Hamas has emerged from its political isolation as its parent movement, the region-wide Muslim Brotherhood, rose to power in several countries in the wake of last year's Arab uprisings, particularly in Egypt.

The Associated Press and Reuters contributed to this report.