GAZA CITY, Gaza Strip - Israel destroyed the headquarters of Hamas' prime minister and blasted a sprawling network of smuggling tunnels in the southern Gaza Strip on Saturday, broadening a blistering four-day-old offensive against the Islamic militant group even as diplomatic efforts to broker a cease-fire appeared to be gaining steam.
In neighboring 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. He said he was working with Turkey, Arab countries, the U.S., Russia and western European countries to halt the fighting.
Israel launched the operation on Wednesday in what it said was an effort to end months of rocket fire out of the Hamas-ruled territory. It began the offensive with an unexpected airstrike that killed Hamas' powerful military chief, and since then has relentlessly targeted suspected rocket launchers and storage sites.
In all, 46 Palestinians, including 15 civilians, have been killed and more than 400 civilians wounded, according to medical officials. Three Israeli civilians have been killed and more than 50 wounded.
Israeli military officials expressed satisfaction with their progress Saturday, claiming they have inflicted heavy damage to Hamas.
"Most of their capabilities have been destroyed," Maj. Gen. Tal Russo, Israel's southern commander, told reporters. Asked whether Israel is ready to send ground troops into Gaza, he said: "Absolutely."
The White House said President Barack Obama was also in touch with the Egyptian and Turkish leaders. The U.S. has solidly backed Israel so far.