JERUSALEM >> An Israeli soldier is missing following a deadly battle in the Gaza Strip, a defense official said Tuesday, as Israeli airstrikes pummeled a wide range of targets along the coastal strip and diplomatic efforts intensified to end more than two weeks of fighting that has killed more than 600 Palestinians and 29 Israelis.

It was not immediately known if the missing soldier was alive or dead, the Israeli defense official told The Associated Press. The disappearance raised the possibility that he had been captured by Hamas — a nightmare scenario for Israel. In the past, Israel has paid a heavy price in lopsided prisoner swaps to retrieve captured soldiers or remains held by its enemies.

Military officials said the soldier, identified as Sgt. Oron Shaul, was among seven soldiers in vehicle that was hit by an anti-tank missile in a battle in Gaza over the weekend. The other six have been confirmed as dead, but no remains have been identified as Shaul, the officials said. They spoke on condition of anonymity because he was not authorized to discuss the incident with media.

Hamas’ claimed earlier this week that it had captured an Israeli soldier. Israel’s U.N. ambassador initially denied the claim but the military neither confirmed nor denied it.

A representative of Shaul’s family, Racheli Gazit, said that “so long as the verification has not been completed … as far as the family is concerned Oron is not a fallen soldier.”

In Cairo, U.N. chief Ban Ki-moon and U.S. Secretary of State John Kerry met Egyptian officials Tuesday in 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.

Israel launched its campaign on July 8 ostensibly to stop Hamas rocket fire into Israel and destroy tunnels the military says Hamas has constructed from Gaza into Israel for attacks against Israelis. The military says Hamas has launched 2,000 rockets since the war began.

Overnight, Israel bombed more than 150 targets, including five mosques, a sports complex and the home of the late Hamas military chief, a Gaza police official said, killing 46 people. Officials also said that among the dead since Monday were six members of a family who had German nationality.

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.

Dozens of journalists and residents of a central Gaza City high-rise evacuated from the building after an Al-Jazeera correspondent said it was hit by Israeli gunfire Tuesday. The correspondent, Tamer al-Misshal, said two bullets hit the building, one puncturing a window.

“We are sure the firing came from Israel and not from Hamas,” al-Misshal said.

Mark Regev, the spokesman for Israel’s prime minister, said “Israel dos not target journalists.”

Tank shells also damaged several houses along the eastern border of the territory, Batniji said. At least 19 fishing boats were burned by Israeli navy shells fired from the Mediterranean Sea, he added.

Eleven people were killed when six upper floors of a Gaza high-rise collapsed onto the two lower stories, buckling them into rubble.

Among the dead were Ibrahim Kelani, 53, his wife Taghreed and their five children, said Ibrahim’s brother, Saleh Kelani, 49. He said Tuesday that his brother and his brother’s children, ranging in age from four to 12, had German citizenship, while his wife did not.

He said his brother lived in Germany for 20 years. Standing outside the morgue of Gaza City’s Shifa Hospital, Saleh Kelani said he was waiting for condemnation of Israel’s actions by the international community, particularly Germany.

“Where is Germany?” he asked, fighting back tears. “When one Israeli is killed all the world talks about it. But six with German nationality? Nothing is happening.”

In Israel, thousands attended the funeral on Monday night of Nissim Sean Carmeli, 21, an Israeli-American soldier from Texas who was killed in the fighting.

“He’s a hero to us and he’s a hero to everyone,” said Seth Greenberg, a friend who tattooed Carmeli’s initials on his neck in the form of a Star of David.

The possibility of a captured soldier raises for Israel past abductions that turned into drawn out mediation with opponents leading to prisoner released. In 2008, Israel released five Lebanese militants in exchange for the remains of two soldiers killed in the 2006 Lebanon war.

Also in 2006, Hamas-allied militants seized an Israeli soldier in a cross-border raid and held him captive in Gaza until Israel traded more than 1,000 Palestinian prisoners for his return in 2011.

Hamas had threatened in the past to kidnap more Israelis and Israel says the militant group’s attacks through tunnels that stretch into Israel are for this purpose.

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 border blockade has set Gaza back years, wiping out tens of thousands of jobs through bans on most exports and on imports of vital construction materials Israel says could be diverted by Hamas for military use. Israel allows many consumer goods into Gaza, but experts say Gaza’s economy cannot recover without a resumption of exports.

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.

Laub reported from Gaza City, Gaza Strip. Associated Press writer Ibrahim Barzak in Gaza contributed to this report.