(GAZA CITY, Gaza Strip) -- Israeli air strikes and rocket launches from the Gaza Strip stretched into a third day, despite talk of a temporary truce.
Israel said it would stop its aerial bombardment of Gaza while Egyptian Prime Minister Hisham Kandil visits the narrow enclave, but Palestinian militants continued to fire rockets toward Israel amid the sounds of Israeli missiles landing in Gaza City.
Israel said more than 150 sites had been targeted overnight, including weapons depots and rocket-launching sites. About 16,000 troops have now been drafted as Israeli troops and tanks mass along the border of the Gaza Strip -- a possible sign of a ground invasion.
Fighting between the two sides escalated sharply Thursday with the first rocket attack from Gaza on Tel Aviv during this burst of violence. No casualties were reported, but three Israelis died in the country's rocket-scarred south when a projectile slammed into an apartment building.
The last time rockets threatened Tel Aviv was during the 1991 Gulf War, when Iraqi President Saddam Hussein fired Scud missiles into the city.
The death toll in the densely populated Palestinian territory stands at 21, including at least six children, according to Palestinian health officials.
Israel says about 300 rockets have flown into Gaza from Israel since Wednesday, some 130 of which were said to have been stopped by the anti-missile Iron Dome system.
Back in Washington, President Obama has been fielding calls from leaders across the Middle East on the mounting violence.
Aboard Air Force One, White House Press Secretary Jay Carney told reporters on Thursday that the administration strongly condemns the ongoing rocket fire from Gaza.
"Hamas claims to have the best interest of the Palestinian people at heart, yet it continues to engage in violence that is counterproductive to the Palestinian cause," Carney said.
Israeli has targeted more than 250 sites across Gaza, which is controlled by Hamas, since the operation dubbed "Pillar of Defense" began Wednesday evening.
The first strike was on Ahmed Jabari, the chief of staff of the military wing of Hamas, the Ezzedeen al-Qassam Brigades. It was followed by a wave of air strikes on other militants, buildings and installations, notably launching sites and rockets, which included the long-range Fajar rockets.
Gaza Hamas Prime Minister Ismail Haniyeh vowed revenge for Jabari's death. "His blood will not be in vain," Haniyeh said.
The last time the region saw this degree of violence was four years ago, when Israel conducted air and ground invasions of Gaza. That operation lasted three weeks and left more than 1,400 people dead.
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