Israel said it may expand an assault on the Gaza Strip amid a fifth day of rocket attacks on its cities, as regional leaders raced to broker an accord ending a conflict that has killed 67 Palestinians and three Israelis.
"We have extracted a heavy price from Hamas and other terrorist organizations, and the army is prepared to significantly widen the operation," Israeli Prime Minister Benjamin Netanyahu said at the weekly Cabinet meeting Sunday in Jerusalem. He said he spoke with President Obama over the weekend and will continue talks with international leaders, according to an e-mailed statement from his office.
Hamas, which controls the Gaza Strip, is considered a terrorist group by Israel, the United States and the European Union.
The violence threatens a region still unbalanced after a wave of popular uprisings last year, including one in Israel's neighbor Syria that has become a civil war.
An Israeli official arrived at the Cairo airport Sunday, an Egyptian security official said, speaking on condition of anonymity because he wasn't authorized to comment to the media. The arrival comes as Egypt's President Mohamed Mursi and Turkey's Prime Minister Recep Tayyip Erdogan have pushed to secure a cease-fire between Hamas and Israel.
Egyptian Foreign Ministry spokesman Amr Roushdi, contacted by text message, said he had no information "whatsoever" on the arrival. Israeli government spokesman Mark Regev declined to comment on the report.
Amid the cease-fire talk, air-raid sirens sounded twice in Tel Aviv Sunday as four rockets were intercepted by Israel's Iron Dome missile-defense system. A rocket was fired at Jerusalem on Friday, the first such attack in decades. At least 73 rockets were fired from Gaza Sunday, raising the number since Wednesday to about 900, according to the Israel Defense Forces. Some 14,000 have been fired from the territory in the past 11 years.
The Israeli strikes killed 15 Palestinians in Gaza Sunday, including 11 members of an extended family by the name of Al- Dalou, said Ashraf al-Qedra, spokesman for the Hamas-run Gaza Health Ministry. At least half of the Palestinians killed in the Israeli airstrikes since Wednesday were civilians, including women and children, he said.
Israel says its military goal is to make Palestinians in Gaza stop firing the rockets that have killed three Israeli civilians.
"Let's understand what the precipitating event was that was causing the crisis, and that was an ever-escalating number of missiles," Obama said at a press conference in Bangkok, where he began a three-nation trip. "We will continue to support Israel's right to defend itself."
U.S. Sen. Joe Lieberman, I-Conn., who spoke Sunday on "Fox News Sunday," called Hamas "bad actors" and said "no nation would put up with what Israel has up until now." On the same show, Sen. Saxby Chambliss, R-Ga., said, "If sending in ground troops in is the only way they can clean out these nests of rockets being fired at them, you know, you can't blame them for doing it."
Hamas said the Israeli actions won't stop it from operating.
"The government and the Palestinian people are united to confront the aggression," it said in an e-mailed statement Saturday. "It is the right of Palestinian people and the government to resist the occupation."
The Iron Dome, which targets projectiles heading toward populated areas, has intercepted 260 of those fired from Gaza, according to the Israeli army.
"We are not yet at the point to be talking about a cease- fire," Uzi Landau, Israeli minister of energy and water, said on Army Radio. Israel is still in the middle of the Gaza conflict, Israeli Defense Minister Ehud Barak said in an e- mailed statement.
World leaders including Obama have called for an end to the conflict before it escalates further. Israel deployed tanks near the border, threatening the first ground invasion of Gaza since an assault that began in December 2008 and left more than 1,100 Palestinians and 12 Israelis dead.
Egypt is trying with Turkey, Arab nations and the world's leading powers, such as the U.S., France and Britain, to get a cease-fire agreement from both sides, Mursi said Saturday.
Israel risks losing "a lot of international support and sympathy" if it mounts a ground invasion to stop the rocket attacks, British Foreign Secretary William Hague told Sky News television Sunday.
Israeli fighter jets hit 50 targets in Gaza overnight, bringing the number of air strikes over the past four days to 950, an army spokesman said, speaking anonymously in compliance with military rules.
Among the targets were buildings housing several media offices, one of which the army said in an e-mailed statement contained a Hamas communications antenna. That prompted the Foreign Press Association to issue a statement of concern. Among the news organizations housed in one of the buildings are Germany's ARD TV and Britain's Sky News, the association said in an e-mailed statement. Russia Today television said in a statement that its office in the same building was destroyed.
The standoff in Gaza is putting pressure on Arab leaders such as Mursi, who came to power after an uprising that ousted U.S. ally Hosni Mubarak last year and has pledged stronger support for Palestinians. Tens of thousands have rallied in Cairo to protest the Israeli attacks, and there were similar demonstrations in Turkey, Iran and other Islamic countries.
Palestinian Authority President Mahmoud Abbas, whose Fatah group rules in the West Bank, has said he'll seek to upgrade Palestinian diplomatic status at the United Nations later this month to "non-member observer state" in the 193-member General Assembly. Abbas failed last year to secure approval in the 15- member Security Council for statehood recognition after opposition from the U.S.
Israeli leaders say the Palestinian bid is a unilateral step to obtain statehood without negotiating, and will be used to try to isolate Israel diplomatically.
"If we see a further escalation of the situation in Gaza, then the likelihood of us getting onto any two-state solution is pushed further in the future," Obama said Sunday. "It starts with no more missiles fired into Israel's territory."
Sen. John McCain, R-Ariz., suggested using an envoy such as former President Bill Clinton to start negotiations.
"We need a person of enormous prestige and influence to have these parties sit down together," McCain said on CBS's "Face the Nation."
Qatari Prime Minister Hamad bin Jasim bin Jabr Al Thani Saturday took his regional counterparts to task for failing to do more for the Palestinian cause, while ruling out any sort of military intervention in the Gaza Strip conflict.
"Our meetings have become a waste of time and public finances," Sheikh Hamad said at an Arab League meeting Saturday in Cairo. "We Arabs have helped in the besieging of our Palestinian brothers."
The Arab League urged its member nations to end normalization of relations with Israel because of the Israeli air offensive in Gaza, Arab League Secretary-General Nabil el- Arabi said in a statement after the meeting in Cairo.
The league has endorsed the so-called Arab Peace Initiative, which was originally proposed in 2002. It offers to normalize relations between Israel and all Arab states in exchange for a complete Israeli withdrawal from territories Israel captured in the 1967 Middle East War, including the West Bank, east Jerusalem, the Gaza Strip and the Golan Heights. Egypt and Jordan are the only Arab League members that have full diplomatic relations with Israel.
Hamas may want to prolong the conflict for a while "to keep earning more popular support among the Arab peoples and Arab leaders," said As'ad Abu Sharkh, a political science professor at Al-Azhar University in Gaza City.
The group probably isn't interested in a "fragile" cease- fire that could be violated, Abu Sharkh said. Instead, it seeks "a long-term truce with guarantees that Israel won't violate it again," so that Palestinians can rebuild Gaza, he said.
Israeli ministers agreed to raise the military reservists' call-up quota to 75,000 from 30,000 at a meeting late Friday in Tel Aviv, said Mark Regev, the spokesman for Netanyahu.
— With assistance from Hans Nichols and Zaid Sabah Abd Alhamid in Washington, Tarek El-Tablawy and Abdel Latif Wahba in Cairo, Deema Almashabi in Riyadh, Selcan Hacaoglu in Ankara, Gwen Ackerman in Jerusalem and Jonathan Ferziger in Tel Aviv.