GAZA CITY, Gaza Strip -- An Israeli bomb pummeled a Gaza City home deep into the ground Sunday afternoon, killing 11 people, including nine in three generations of a single family, in the deadliest single strike since the cross-border conflict between Israel and the militant faction Hamas escalated Wednesday.
The airstrike, along with several others that killed civilians across this coastal territory and hit two media offices in this city -- one of them used by Western TV networks -- further indicated that Israel was striking a wider range of targets. Gaza health officials reported that the number of people injured had nearly doubled to 600 by day's end; the Palestinian death toll climbed to 70, including 20 children. Three Israelis have been killed and at least 79 wounded by continued rocket fire into southern Israel and as far north as Tel Aviv, as Israeli cities were paralyzed by an onslaught of relentless rocket fire out of Gaza for the fifth straight day.
Even as President Barack Obama, beginning an Asia visit, supported Israel's "right to defend itself," he also said that "if that can be accomplished without a ramping up of military activity in Gaza, that's preferable." And he described an urgent international effort to secure a cease-fire, saying, "We're going to have to see what kind of progress we can make in the next 24, 36, 48 hours."
British Foreign Secretary William Hague warned that Israel would lose support from the international community if it followed through on threats to deploy troops in Gaza.
Cease-fire negotiations in Cairo appeared to make little headway Sunday, although Hamas' newly strong standing was underscored as the group's top leader in exile, Khaled Meshal, met with Egyptian President Mohamed Morsi and Turkish Prime Minister Recep Tayyip Erdogan. Hamas made sweeping demands, including the permanent opening of the border crossing between Gaza and Egypt, and the end of the Israeli blockade.
An Israeli envoy arrived in Cairo on Sunday, The Associated Press reported, citing anonymous Egyptian security sources, but as fighting in Gaza escalated, it was far from clear whether the visit was a prelude to a deal. U.N. Secretary General Ban Ki-moon planned to visit Cairo today to discuss the situation.
Israel's Prime Minister Benjamin Netanyahu, meanwhile, has stuck to his demand that all rocket fire cease before the Israeli campaign lets up, and tanks and troops remained lined up outside Gaza on Sunday. Tens of thousands of reserve troops had been called up. "The army is prepared to significantly expand the operation," Mr. Netanyahu said at the start of a Cabinet meeting.
In the Israeli strike Sunday morning, it took emergency workers and a Caterpillar digger more than an hour to reveal the extent of the devastation under the two-story home of Jamal Dalu, a shop owner. Mr. Dalu was at a neighbor's when the blast wiped out nearly his entire family: His sister, wife, two daughters, daughter-in-law and four grandchildren ages 2 to 6 all perished under the rubble, along with two neighbors, an 18-year-old and his grandmother.
Ismail Haniyeh, the prime minister of the militant Hamas faction that rules Gaza, condemned the attack as a "massacre" that "exceeded all expectations."
Brig. Gen. Yoav Mordechai, chief spokesman for the Israeli military, said it was "examining the event."
"The wanted target in this case was responsible for firing dozens of rockets into Israel," he added. "I do not know what happened to him, but I do know that we are committed to the safety of the citizens of Israel."
Momentarily lulled by a quiet night, Israelis awoke Sunday to a new blitz of Palestinian rockets that totaled nearly 100 by nightfall, including two that soared toward the population center of Tel Aviv but were knocked out of the sky by the so-called Iron Dome missile defense system.
One rocket crashed through the roof of an apartment building in Ashkelon, a few miles up the coast from Gaza, where residents escaped serious injury because they had heeded the warning siren and run to lower floors. Four people were injured, two of them seriously, when a rocket exploded near their car in Ofakim, and a firefighter in Nachal Oz was seriously hurt by shrapnel.
A barrage of 10 missiles rained on Ashdod; nine were intercepted and the 10th hit an eight-story building but did not explode, heightening fears as residents were told to remain inside.
There are no warning sirens in the Gaza Strip, where the wee hours of Sunday were punctuated by airstrikes as well as a series of missiles fired from Israeli Navy vessels off the coast.
Later in the morning, Mutassim Essifan, 5, and his 1-year-old sister, Jumana, were killed in the Jabiliya Refugee Camp near the northern border, followed by another baby in the Al Buraj Refugee Camp mid-strip and, by lunchtime, a 52-year-old woman in the eastern part of Gaza City. Ahmed Al-Nahal, 24, a member of Hamas' military wing, and his relative Tasnim, 8, were killed before lunchtime in the Beach Refugee Camp, where Mr. Haniyeh lives.
Among the buildings Israel hit overnight were two containing the offices of local media outlets, in what the military described as an attempt to derail Hamas communications.
The Washington Post contributed.