Palestinians stormed a U.N. compound on Sunday during a protest against Israeli airstrikes that killed dozens of civilians in Qana, Lebanon, and security officials fired into the air to disperse them.

The protesters smashed windows of the UNSCO building with rocks after marching through Gaza City in the demonstration. At least seven people were wounded, including four policemen, officials at the Al-Quds and Shifa hospitals said. Five of the injured were hit by rocks and the other two by ricochets from the gunfire, the officials said.

The protesters — who were waving Lebanese and Hezbollah flags, and burning U.N. flags — quickly dispersed when Palestinian President Mahmoud Abbas ordered Presidential Guards and Palestinian police to close the compound. Besides the Office of the United Nations Special Coordinator, the compound also includes U.N. headquarters, the World Bank and the presidential Guest Palace, where important guests visiting the Gaza Strip stay.

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U.N. envoy Alvaro De Soto said some local U.N. staffers were evacuated from the building at the time of the attack.

Asked why the U.N. was targeted, he said in an interview: "They were venting their anger against the international community about the current situations" in Gaza and Lebanon.

At least 56 people, more than half of them children, were killed Sunday in an Israeli airstrike on Qana, Lebanon, infuriating Lebanese officials and leading other countries to step up their calls for an immediate cease-fire in Israel's offensive in Lebanon.

Israeli forces also have been fighting an offensive against Hamas-linked militants in Gaza for more than a month, and the militants and many members of the public have strongly supported the Hezbollah guerrillas fighting Israeli forces in Lebanon.

The offensive began after militants raided an Israeli outpost and killed two soldiers and captured another. Israel also is trying to stop militants from firing dozens of homemade rockets from Gaza into southern Lebanon.

On Sunday night, Israel's air force destroyed a vacant house in the northern town of Beit Lahiya that belongs to a Hamas activist, witnesses said. It had been evacuated after Israeli forces warned of an impending attack. Nearby houses also were damaged, but no casualties were reported.

About 100 Gazans, many of them gunmen, have been killed in the offensive, during which Israeli forces have destroyed government buildings, bridges, the territory's only power station and many homes.

"Today is the day of rage," said a chant blasted from a loudspeaker during Sunday's anti-Israel, pro-Hezbollah march through Gaza City.

"From Gaza to Qana, a flood of Arab blood is streaming," read one poster held up by young Palestinians.

Protesters held empty coffins covered with pictures of young Palestinians killed in the monthlong offensive in Gaza.

"Yesterday in Gaza, today in Lebanon. Where is it going to be next?" asked Amer al-Sawafiri, a government employee who took part in the protest.

Osama Hamdan, a Hamas leader in Lebanon, told the Arab satellite news channel Al-Jazeera that the Qana attack would be met with an escalation of militant operations against Israel. "The resistance now is interested in escalating its operations. I think this resistance is responsible to protect not only the Lebanese and Palestinian people," he said.

He called on Hamas field leaders to "surprise" Israel with more attacks.

Palestinian leaders on Sunday condemned Israel's attack on the Lebanese village of Qana and called for an immediate cease-fire in southern Lebanon.

Abbas, on a tour of foreign countries, condemned the attack in the "strongest possible terms," said Palestinian lawmaker Saeb Erekat, an Abbas confidant.

Palestinian Prime Minister Ismail Haniyeh called the Qana attack a "horrific" war against humanity, and accused Israel of endangering regional stability.

"Today we are witnessing a horrific war against humanity and all values and morals whether in Palestine or Lebanon," Haniyeh said at the start of a Cabinet meeting in Gaza City. "It is (Israel) that threatens the security of the peoples and stability of the region ... by intentionally killing civilians, and expanding the circle of war."

Haniyeh called on the United Nations to impose penalties on Israel.

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