An explosion rises from an Israeli airstrike in Gaza City on Saturday. Israel bombarded the Gaza Strip with at least 300 airstrikes Saturday.
By IBRAHIM BARZAK and JOSEF FEDERMAN The Associated Press
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 United States, Russia and western European countries to halt the fighting.
Israel launched the operation 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 Obama was also in touch with Egyptian and Turkish leaders. The United States has solidly backed Israel so far.
"We believe Israel has a right to defend itself, and they'll make their own decisions about the tactics they use in that regard," deputy national security adviser Ben Rhodes told reporters on Air Force One.
Despite the bruising offensive, Israel has failed to slow the barrages of rockets from Gaza. The Israeli military said 160 rockets were launched into Israel on Saturday, raising the total number to roughly 500 since last week's fighting began. Eight Israelis, including five civilians, were lightly wounded Saturday, the army said.
Israel carried out at least 300 airstrikes Saturday, the military said, and broadened its array of targets. One air raid flattened the three-story office building used by Hamas' prime minister, Ismail Haniyeh. He was not inside the building at the time.
In southern Gaza, aircraft went after the tunnels that militants use to smuggle in weapons and other contraband from neighboring Egypt. Tunnel operators said the intensity of the bombing was unprecedented, and that massive explosions could be heard miles away, both in Gaza and in Egypt.
Missiles also smashed into two small security facilities and the massive Hamas police headquarters in Gaza City, setting off a huge blaze that engulfed nearby houses and civilian cars parked outside, the Interior Ministry reported. No one was inside the buildings.
Air attacks knocked out five electricity transformers, cutting off power to more than 400,000 people in southern Gaza, according to the Gaza electricity distribution company. People switched on backup generators for limited electrical supplies.
Hamas unveiled an arsenal of more powerful, longer-range rockets last week, and for the first time struck at Israel's two largest cities, Jerusalem and Tel Aviv. Both cities, more than 45 miles from Gaza, had previously been beyond rocket range.
In a psychological boost for Israel, a new rocket-defense system known as "Iron Dome" knocked down a rocket headed toward Tel Aviv, eliciting cheers from relieved residents huddled in fear after air raid sirens sounded in the city.
Police said a second rocket also targeted Tel Aviv. It was not clear where it landed or whether it was shot down. No injuries were reported. It was the third straight day the city was targeted.
Israel has vowed to stage a ground invasion, a scenario that would bring the scale of fighting closer to that of a war four years ago.
Israel's Defense Minister Ehud Barak has authorized the emergency call-up of up to 75,000 reserve troops ahead of a possible ground offensive. Israel has massed thousands of troops and dozens of tanks and armored vehicles along the border in recent days.
Egypt, which is led by Hamas' parent movement, the Muslim Brotherhood, has been spearheading efforts to forge a cease-fire. Morsi has vowed to stand strong with the people of Gaza and this week recalled Cairo's ambassador from Israel to protest the offensive.
Quietly, though, non-Muslim Brotherhood members in Morsi's government are said to be pushing Hamas to end its rocket fire on Israel. Morsi is under pressure not to go too far and risk straining ties with Israel's ally, the United States.
The Hamas website said Saturday that its leader, Khaled Meshaal, met with the head of Egyptian intelligence for two hours Saturday in Cairo, a day after the Egyptian official was in the Gaza Strip trying to work out an end to the escalation in violence.
Hamas has not immediately accepted Egypt's proposal for a cease-fire, but the group's website said it could end its rocket fire if Israel agrees to end "all acts of aggression and assassination" and lift its five-year Israeli blockade on Gaza. Egypt will present the Hamas position to Israeli officials.
Israeli officials say they are not interested in a "timeout," and want firm guarantees that the rocket fire, which has paralyzed life in an area home to 1 million Israelis, finally ends. Past cease-fires have been short lived.
Morsi warned that a ground operation by Israel will have "repercussions" across the region. "All must realize the situation is different than before, and the people of the region now are different than before and the leaders are different than before," he said at a joint news conference with Turkey's Islamist prime minister, Recep Tayyip Erdogan.
Erdogan, like Morsi, leads an Islamist government that has chilly diplomatic ties with Israel.Tweet