Israel bombarded the Hamas-controlled Gaza Strip Saturday with more than 300 airstrikes and shot down a rocket fired at Tel Aviv, said the military.

Targets included the Hamas prime minister’s headquarters, a police compound and a network of tunnels used to smuggle in weapons and other contraband from Egypt.

The Israel Defense Forces described its attacks in a series of tweets, in addition to posting pictures and videos online.

“This morning, the IDF targeted Mohammed Kaleb, a senior member of #Hamas’ air defense unit in #Gaza,” read a tweet posted using the Twitter handle @IDFspokesperson.

The latest airstrikes, which officials in Gaza say killed 15, came as Palestinian militants fired more than 100 rockets toward Israel, with two aimed at Tel Aviv.

Rocket attacks launched on Tel Aviv and Jerusalem this week mark the first time Gaza militants have managed to fire rockets towards the cities.

Egypt hosts cease-fire talks

The airstrikes and rocket attacks came just as attempts to broker a cease-fire gained momentum. Hamas leaders and officials from allies Qatar and Turkey had met in Cairo for talks with Egyptian representatives, and the Arab League was in the process of holding an emergency meeting.

“There are discussions about the ways to bring a cease-fire soon, but there are no guarantees until now," Egyptian President Mohammed Morsi said at a news conference.

Egypt has been leading the efforts to broker a cease-fire. Morsi, who represents the Muslim Brotherhood, has vowed to stand with the Gaza residents. This week, he recalled Cairo’s ambassador from Israel to protest the offensive.

However, Morsi faces pressure to not go too far in his support of Hamas militants for fear of straining relations with the U.S., Israel’s strong ally.

According to the Hamas website, leader Khaled Meshaal met with the head of Egyptian intelligence on Saturday in Cairo.

Hamas has not formally accepted Egypt’s proposal for a cease-fire, but the group’s website said it would end its rocket attacks if Israel agrees to end its offensive and lift a five-year blockade on Gaza. Egypt will present Hamas’ offer to Israeli officials.

However, Israeli officials say they want guarantees that the rocket fire will end. Past cease-fires have been fleeting.

Israeli Prime Minister Benjahim Netanyahu defended his position while speaking with leaders of Britain, Poland, Portugal and Bulgaria.

“No government in the world would allow a situation where its population lives under the constant threat of rockets," Netanyahu told them, according to a statement from his office.

U.S. President Barack Obama was also in touch with Egyptian and Turkish leaders, the White House confirmed.

National security advisor Ben Rhodes said the White House believes Israel “has the right to defend itself” against attacks and that Israelis will decide for themselves what “military tactics and operations” they will proceed with.

As the number of targets increases, the scale of fighting approaches that of the 2008 war between Israel and Gaza fighters.

Hamas emerged from that war badly bruised, but has since rebuilt its arsenal with better weapons. The group has also faced pressure from more militant groups to renew its commitment to fighting Israel.

Israel downs rocket heading for Tel Aviv

On Saturday, an Israeli rocket defence system dubbed “Iron Dome” knocked down a rocket heading towards Tel Aviv. Residents cheered as the rocket fell and air raid sirens blared through the city.

Police said a second rocket was also fired off toward Tel Aviv. It is not known where the rocket landed or if it was shot down. No injuries were reported.

Israel said the Iron Dome system has shot down about 250 incoming rockets, mostly in the southern part of the country.

Saturday marked the first time Iron Dome has been used in Tel Aviv.

The conflict began after Israel launched a surprise airstrike on Wednesday that killed Hamas’ military chief, a move it said was in retaliation for an increase in rocket attacks from Gaza in recent months. Israel then fired on dozens of rocket launchers and storage sites in Gaza.

Despite Israel’s claims to be exacting massive damage on Hamas rulers in Gaza, it has not been able to slow the rocket attacks coming from Gaza.

In total, 48 Palestinians, including 15 civilians, have been killed. Three Israel civilians have died and more than 50 have been wounded since the conflict began.

Israel ‘absolutely’ ready for ground operation: Israeli official

Israeli officials maintain that Hamas has suffered since the offensive began.

“Most of their capabilities have been destroyed,” said Israeli southern commander Maj. Gen. Tal Russo. Russo also said Israel is “absolutely” ready to send ground troops into Gaza if it needs to.

“Most of their weapons are stored in civilians’ homes. They launch rockets from residential areas. We do not want to hit civilians in Gaza, but we do want to hit  the hornet’s nest of terror in Gaza,” he said.

Israel has authorized the call-up of nearly 75,000 reservists in preparation for a possible ground operation. Armoured vehicles have gathered along the Gaza border in recent days.

But Israeli officials have not yet decided whether to proceed with a ground operation, a decision that will likely lead to heavy casualties on both sides.

Key targets in Gaza attacked

Among the targets attacked in Gaza was the office building of Prime Minister Ismail Haniyeh of Hamas.

Haniyeh’s office building was levelled by an Israeli airstrike that blew out windows in neighbouring homes. Haniyeh was not in the office at the time.

Another airstrike smashed the home of a Hamas commander in the Jebaliya refugee camp close to Gaza City. The commander was wounded and other residents of the building were injured, said medics.

Missiles destroyed a massive Hamas police headquarters in Gaza City. The missiles sparked a huge fire that engulfed nearby houses and parked cars, reported the Interior Ministry. No one was inside the buildings at the time.

The Interior Ministry also reported that a government compound was hit while Muslims were heading to the area for early morning prayers. No casualties were reported from the assault.

A series of underground tunnels used by militants to smuggle weapons from Egypt were also hit, residents said. The huge explosions caused buildings in the Egyptian city of El-Arish -- located roughly 45 kilometres away -- to shake, reported AP.

With files from The Associated Press