Calm returned to the suburbs of the Lebanese capital Monday as intensive diplomatic efforts continued in a bid to prevent further escalation of political tensions after a man was killed in clashes between Sunni and Shiite Muslims.

Traffic was closed in central Beirut, Lebanon's capital, as the sit-in protest by supporters of the Shiite Muslim Hezbollah and its allies entered its fourth day Monday in bid to bring down the government.

Soldiers and police, backed by tanks and armored vehicles continued to surround government headquarters in a protective cordon. were surrounded by a protective cordon of tanks, soldiers and police.

The political standoff between Prime Minister Fuad Saniora's government and the opposition, led by Hezbollah, turned violent Sunday leaving a Shiite man dead from gunshot wounds and 21 others injured.

Arab League Secretary General held separate meetings Sunday with leaders of the feuding sides, including Saniora and Parliament Speaker Nabih Berri, whose Shiite political party is allied to the Hezbollah-led pro-Syria camp.

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Moussa also held a midnight meeting with personal representatives of Hezbollah leader Sheik Hassan Nasrallah and was expected to meet with President Emile Lahoud at the presidential palace.

No details of the talks were disclosed, but the media quoted Moussa as saying he was not carrying an initiative, but "proposing ideas, hoping to formulate a framework" to help the country emerge from the current crisis.

Lebanon's Al-Nahar newspaper quoted Moussa as saying: "National consensus is the basis for any Arab action. We are working for Lebanon and must work things out on the basis of national unity."

Although the open-ended sit-in that began Friday has been peaceful, it has notched up anxiety in this multi-sectarian society that the political impasse could erupt into widespread sectarian violence.

Saniora, emboldened by Arab and international support for his U.S.-backed government, vowed on Sunday to stay in office despite the ongoing protests. He warned that any attacks on Cabinet headquarters where he and several of his ministers were staying could spark sectarian fighting.

Rival Masses held Sunday by Saniora's anti-Syrian bloc and Hezbollah's Christian allies, led by Michel Aoun, underlined the interplay of politics and religion in the conflict.

Sunday night's clashes in Tarik Jdideh occurred as a group of Hezbollah supporters were returning from downtown Beirut and passed through the Sunni neighborhood.

Police officials said the two sides threw stones at each other, then shots were fired, killing Ahmed Ali Mahmoud, a 20-year-old Shiite. The officials spoke on condition of anonymity because they were not allowed to speak to the press.

Hezbollah, an ally of Syria that is backed by many Shiite Muslims and some Christians, contends the fight is against American — not Syrian — influence, saying the United States now dominates Lebanon in the interests of Israel.

In Jerusalem, Israeli officials on Sunday warned that the fall of Saniora's moderate government could lead to the establishment of an Iranian proxy state on Israel's northern border and increase the probability of war between the two nations.

Lebanon's internal political tension escalated sharply in November when six pro-Hezbollah ministers resigned from the Cabinet last month after Saniora and his anti-Syrian majority in parliament rejected the group's demand for a new national unity government that would effectively give it and its allies veto power.

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