Local television footage showed heavily-armed soldiers attempting to disperse clashing youth and extensive gunfire could be heard in several neighborhoods in the capital, as masked men armed with assault rifles could be seen hiding in alleyways and hand grenades lying beneath cars.

There was no confirmation on casualties, but ambulance rushed toward hospitals with sirens screaming.

Angry crowds burned the party flags of their foes and reports said opposition supporters stormed and occupied an office of the pro-government Future bloc, led by MP Saad Hariri.

Opposition followers blocked main roads with burning tires, old cars and truckloads of dirt, cutting off access to central Beirut as well as the airport and sea port as a general strike – supported by the opposition – was observed to protest low wages and declining living conditions.

The head of the General Confederation of Labor Unions, Ghassan Ghosn, said the syndicates had called off a demonstration demanding better pay, because the government authorities were unable to provide the protesters with sufficient security.

The government retorted by accusing the Shiite Hezbollah organization of turning a peaceful demonstration into a "militia operation" and shifting attention from social and economic demands into political ones.

Lebanese commentators said violent clashes and blocked roads were expected after the cabinet on Tuesday dismissed the head of airport security, Brig-Gen. Wafiq Shukair, for allegedly permitting the Shiite group to install spy cameras at the airport to monitor the movements of anti-Syrian politicians and foreign officials and for declaring Hezbollah's private telecommunication network illegal.

An independent analyst told the Middle East Times the government's decisions virtually meant it had "declared war" on Hezbollah, and the group was expected to demonstrate "who can control the streets in the event of a showdown."

The army, at times firing bullets in the air, managed to prevent the confrontations from spiraling out of control, but soldiers made no attempt to remove the truckloads of dirt that blocked the airport road near Hezbollah strongholds in Beirut's southern suburbs.

Hezbollah followers supervising the closure of the airport road said that access will remain closed so long as the government of Prime Minister Fouad Siniora – backed by the United States and its Western and Arab allies – remained in power.

The army has so far remained neutral and united in Lebanon's deepest crisis since the end of its 1975-1990 civil war, taking exceptional caution by resisting any stringent measures that could provoke either side of the divide.

The country, still managing to function without a president since last November, is split between the ruling coalition of Sunni, Christian and Druze politicians and an opposition alliance of Shiites and Christians, backed by Iran and Syria.

Some analysts warned that Wednesday's battles, the worst since armed clashes erupted in January 2007 during an anti-government protest, could be the start of a new level of confrontation between the government and the Hezbollah-led opposition.

While many politicians and analysts continue to rule out the possibility of an all-out war because, they say, all feuding parties realize there could be no winners in such a confrontation, some suggest that Hezbollah and its allies will intensify their campaign against the government.

Sources close to the opposition told the Middle East Times that Wednesday's action in blocking main roads was the start of a larger civil disobedience campaign to pressure the government to retract its decisions that targeted Hezbollah.

The organization's secretary-general, Sayed Hassan Nasrallah, a leading icon for most Shiites here, is to give a news conference on Thursday to declare Hezbollah's position and what reaction it will have to the cabinet's two-pronged move: illegalize its telecommunication network and reassigning Shukair to the army.

Officials from the organization, whose armed wing is credited with liberating southern Lebanon from Israeli occupation in 2000 and fiercely fighting the Israelis in the 2006 war, said the network was part and parcel of Hezbollah's weapons against Israel, and that any attempt to dismantle its telecommunication system was an attempt to weaken the resistance against Israel.

Hezbollah and its opposition allies already disregard the government and its decisions as "illegitimate," after six cabinet ministers – five of them Shiites – resigned in November 2006, and have virtually paralyzed the government by blocking off much of the trendy downtown area with sit-in tents since December of the same year.

Analysts said Hezbollah's successful efforts Wednesday to disrupt much of Beirut, sent a message to all that its followers have the ability to "rule the streets" if the government chooses to provoke it into a face-off. However, Hezbollah has repeatedly stressed it would not be pushed into turning its weapons against its Lebanese foes.