GAZA CITY — Israeli airstrikes pummeled a wide range of targets in the Gaza Strip on Tuesday as the U.N. chief and the U.S. secretary of state began an intensive effort to end more than two weeks of fighting.

Overnight, Israel bombed five mosques, a sports complex and the home of the late Hamas military chief, a Gaza police official said.

The Israel military announced early Tuesday that two more soldiers had died, one from sniper fire on Monday and one from still unexplained causes, bringing the military death toll to 27. It's the highest number of Israeli military fatalities for any campaign since the 2006 Lebanon war. Two Israeli civilians have also been killed in the latest conflict.

The Israeli campaign, launched July 8, is aimed at stopping Hamas rocket fire into Israel — some 2,000 rockets have been launched over the past two weeks, the military says — and destroying tunnels the military says Hamas has constructed from Gaza into Israel for attacks against Israelis.

The airstrikes set off huge explosions that turned the night sky over Gaza City orange early Tuesday. The sound of the blasts mixed with the thud of shelling, often just seconds apart, and the pre-dawn call to prayer from mosque loudspeakers.

The strikes came as U.N. chief Ban Ki-moon and U.S. Secretary of State John Kerry met in Cairo late Monday to launch the highest-level push yet to end the deadly conflict. The U.N. has said that the majority of the Palestinians killed were civilians, among them dozens of children.

In the Gaza Strip, Israeli aircraft hit more than 70 targets, including the home of the late leader of Hamas' military wing, five mosques and a sports complex, said Gaza police spokesman Ayman Batniji. There were no casualties in the mosques or at the sports complex, which includes a gym, three martial arts studios and a soccer field.

Egypt, Israel and the U.S. back an unconditional cease-fire, to be followed by talks on a possible new border arrangement for Gaza. Israel and Egypt have severely restricted movement in and out of Gaza since Hamas seized the territory in 2007.

Hamas, with some support from Qatar and Turkey, wants guarantees on lifting the blockade before halting fire. The Islamic militant group has no faith in mediation by Egypt's rulers, who deposed a Hamas-friendly government in Cairo a year ago and tightened restrictions on Gaza — to the point of driving Hamas into its worst financial crisis since its founding in 1987.

The top Hamas leader in Gaza, Ismail Haniyeh, said Monday that Gaza's 1.7 million people share Hamas' goal of forcing Israel and Egypt to lift the blockade.

"We cannot go back, we cannot go back to the silent death" of the blockade, he said. "Gaza has decided to end the blockade by its blood and by its courage."

After a meeting with Egyptian Foreign Minister Sameh Shukri, Ban said that "violence must stop by all sides," and that they must enter negotiations, apparently siding with Cairo's approach.

"We can't claim victory simply by returning matters to where they stood before they led to terrible bloodshed," Ban said.

On Monday, President Barack Obama reaffirmed his belief that Israel has the right to defend itself against rockets being launched by Hamas into Israel. Yet, he contended that Israel's military action in Gaza had already done "significant damage" to the Hamas terrorist infrastructure and said he doesn't want to see more civilians getting killed.

On arriving in Cairo, Kerry announced the U.S. will send $47 million in humanitarian aid for tens of thousands of Palestinians who fled their homes in the coastal territory to escape the violence. Kerry's top aides warned, however, that achieving an immediate and lasting cease-fire would be difficult and he hoped to make any progress over the next several days to secure even a temporary pause in the bloodshed.

It's not clear exactly what Israel and Hamas would each demand in return for agreeing to a truce now, but senior State Department officials said the issue of opening border crossings — potentially into Israel and Egypt — was under discussion.

"We will work to see if there is some way to not only arrive at a cease-fire of some kind but to get to a discussion about the underlying issues," Kerry said at the start of his meeting with Ban. "Nothing will be resolved by any cease-fire, temporary or long, without really getting to those issues at some point and that's what we need to do."

Kerry remained in Cairo on Monday for more meetings with top Egyptian officials. But there were no immediate plans for face-to-face meetings with officials from Qatar, Turkey, Israel and the West Bank.