Israeli forces pounded the Gaza Strip on Wednesday, sending thousands of residents fleeing, and said it was meeting stiff resistance from Hamas Islamists, as U.S. Secretary of State John Kerry flew to Tel Aviv to push ceasefire talks.

In a blow to Israel's economy, U.S. and many European air carriers halted flights to the country citing security worries after a militant rocket from Gaza hit a house near Ben Gurion airport. Israel urged a re-think, saying its airspace was safe.

Making an unannounced, one-day visit, Kerry was due to see Israeli Prime Minister Benjamin Netanyahu, Palestinian President Mahmoud Abbas and U.N. Secretary General Ban Ki-moon, signaling an intensification of efforts to end the bloodshed.

Israel launched its offensive on July 8 to halt missile salvoes by Hamas Islamists, who were struggling under the weight of an Israeli-Egyptian economic blockade and angered by a crackdown on their supporters in the nearby occupied West Bank.

After failing to halt the militant barrage through days of aerial bombardment, Israel sent ground troops into Gaza last Thursday, looking to knock out Hamas's missile stores and destroy a vast, underground network of tunnels.

Some 643 Palestinians, many of them children and civilians have died in the conflagration, including a seven-year-old hit by a shell in southern Gaza early Wednesday, a medic said.

Some 29 Israeli soldiers have been killed, including a tank officer shot by a Palestinian sniper overnight. Two civilians have been slain by rocket fire. The military says one of its soldiers is also missing and believes he might be dead. Hamas says it has captured him, but has not released his picture.

Clouds of black smoke hung over the densely populated Mediterranean enclave, with the regular thud of artillery and tank shells filling the air.

"We are meeting resistance around the tunnels ... they are constantly trying to attack us around and in the tunnels. That is the trend," said Israeli military spokesman Lieutenant-Colonel Peter Lerner.

He said 30 militant gunman had been killed overnight, bringing the total to 210 since the offensive started.

Hamas's armed wing, the Izz el-Deen Al-Qassam, said its fighters had detonated an anti-personnel bomb as an Israeli army patrol passed, killing several troops. There was no immediate confirmation from Israel.

There was also violence in the occupied West Bank, where a Palestinian was shot dead by Israeli troops near Bethlehem. The army said soldiers fired a rubber bullet at him during clashes with Palestinians hurling rocks and Molotov cocktails.

 

PALESTINIAN DEMANDS

The Palestinian decision-making body led by U.S.-backed Abbas on Wednesday endorsed demands by Hamas for halting Gaza hostilities with Israel, a closing of ranks that may help Egyptian-mediated truce efforts.

Egypt has tried to get both sides to hold fire and then negotiate terms for protracted calm in Gaza, which has been rocked by regular bouts of violence since Israel unilaterally pulled out of the territory in 2005.

Hamas, which refuses to recognize Israel's right to exist, has baulked at Cairo's offer, saying it wanted assurances of relief from an Israeli-Egyptian blockade and other concessions. The dispute was further complicated by distrust between Egypt under President Abdel Fattah al-Sisi and Hamas.

In a move that could effectively turn Abbas into the main Palestinian point person for a Gaza truce, his umbrella Palestine Liberation Organization (PLO) on Wednesday formally supported core conditions set by the Hamas-led fighters.

Egyptian sources said a unified Palestinian position could help achieve a deal. Unlike Hamas, the PLO has pursued peacemaking for two decades.

Israel faced mounting international alarm at the civilian death toll, as well as increased economic pressure from lost tourism revenues after the U.S. Federal Aviation Administration (FAA) took the rare step on Tuesday of banning flights to Tel Aviv's Ben-Gurion International Airport for at least 24 hours.

European airlines also canceled flights to Israel, whose own carriers continued to operate.

An Israeli official said Netanyahu had asked Kerry to help restore the U.S. flights. A U.S. official said the Obama administration would not "overrule the FAA" on a security precaution but noted the ban would be reviewed after 24 hours.

 

DEATH, DESTRUCTION

Gaza's Health Ministry said 18 Palestinians were killed on Wednesday, many of them in the southern town of Khan Younis -- one of the focal points of Israel's recent assault.

In the far north, residents continued to flee Beit Hanoun as Israeli tanks thrust deeper into the border town and destroyed nearby orchards in their search for hidden Hamas tunnels.

"Columns of people are heading west of Beit Hanoun, looking for a safe shelter. This is not war, this is annihilation," said 17-year-old Hamed Ayman.

"I once dreamt of becoming a doctor. Today I am homeless. They should watch out for what I could become next," the youth told Reuters.

Gaza officials said that so far in the 16-day conflict, 475 houses had been totally destroyed by Israeli fire and 2,644 partially damaged. Some 46 schools, 56 mosques and seven hospitals had also suffered varying degrees of destruction.

Israel has said it is not targeting civilians and is issuing warnings to residents to quit certain neighborhoods to prevent them from getting engulfed in the fighting. Many locals say they have no place to flee in the narrow, besieged territory.

Because Washington, like Israel and the European Union, deems Hamas a terrorist group, they have no direct contact and Washington must rely on proxies such as Egypt, Qatar and Turkey.

In a sign of the intensity of the U.S. diplomacy, Kerry spoke to Qatari and Turkish foreign ministers after meeting Sisi for two hours, a senior U.S. official said.

"The Egyptians have provided a framework and a forum for them to be able to come to the table to have a serious discussion together with other factions of the Palestinians," Kerry said. "Hamas has a fundamental choice to make and it is a choice that will have a profound impact for the people of Gaza."

Hamas says it will keep fighting until its demands are met, including the release of several hundred supporters recently arrested in the West Bank and a freeing up of Gaza's borders.

Adding to the enclave's woes, residents said Israel shelled their power plant which provides electricity to half the people of Gaza. Electricity supplies from Israel were hit last week, with Israel saying militant rockets had damaged infrastructure.