Political leaders met for the first time in nearly five months Monday for talks designed to bring calm to Lebanon, which has seen bombings and threats to bring down the government by mass demonstrations.

The leaders met in the parliament building in downtown Beirut at the invitation of speaker Nabih Berri, who has warned that unless they settled their disputes, the country would face "dangerous" destabilization.

Hundreds of police officers and soldiers cordoned off parliament in a major security operation that caused huge traffic jams in the city center.

The main items on the agenda are the demand by the militant Hezbollah group and the mainly Christian faction of Michel Aoun for the formation of a new coalition government and a new electoral law.

All the participants of the previous "national dialogues" attended Monday's meeting, except the leader of Hezbollah, Sheik Hassan Nasrallah, who sent his party's chief legislator, Mohammed Raad, because of Israeli threats to assassinate him.

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Last week, Nasrallah caused a stir when he announced that Hezbollah wanted the Cabinet to be reshuffled so as to give his party and its allies a third of the 24 ministerial positions — effectively veto-power.

Nasrallah said that if Prime Minister Fuad Saniora did not grant this, Hezbollah supporters would stage mass demonstrations to bring down the government.

The United States accused Syria and Iran, which back Hezbollah, of trying to topple Lebanon's government — a charge that Syria denied.

Saniora said Nasrallah's demand would be discussed in the all-party talks. And a Christian faction that supports his government threatened to bring its supporters on to the streets if Hezbollah staged large protests.

Pro-government parties want this week's talks to include the future of President Emile Lahoud, a staunch pro-Syrian whom they have been trying to oust for more than a year. Lahoud has rejected repeated calls for him to step down.

The all-party talks began in March but have not taken place since June 25 because of the 34-day war with Israel that began the following month. In the previous sessions, the leaders repeatedly failed to reach consensus on the future of Lahoud and the U.N. Security Council demand for the disarmament of Hezbollah.

Six bombs have detonated in Beirut in recent weeks, wounding six people. The latest bomb exploded in a car park near a police barracks on Sunday night, causing damage but no injuries.

Last year, much larger bombings targeted anti-Syrian figures and commercial centers in Christian areas, killing two prominent anti-Syrian journalists and a politician. The largest explosion was in February 2005, killing former Prime Minister Rafik Hariri and 22 others in central Beirut.

Anti-Syrian groups have accused Damascus of orchestrating the bombings, but Syria has denied this. Syria was forced to withdraw its army from Lebanon last year after Hariri's assassination.