The unrest virtually shut down Lebanon's international airport for a second day and barricades closed major highways. -- PHOTO: REUTERS

BEIRUT, (Lebanon) - RUNNING gunbattles raged in parts of Beirut after the leader of Hizbollah accused Lebanon's Western-backed government of declaring war on his Shi'ite militant group. At least four people were killed and eight wounded in the capital.

In a grim reminder of Lebanon's devastating 1975-90 civil war, factions threw up roadblocks and checkpoints dividing Beirut into sectarian enclaves on the second day of clashes Thursday between Sunni Muslims loyal to the government and Shi'ite supporters of Hezbollah.

A top Sunni leader went on television urging Hezbollah to pull its fighters back and 'save Lebanon from hell.' The army, which has stayed out of the sectarian political squabbling that has paralysed the country for more than a year, did not intervene in the battles.

The chattering of automatic weapons and thumps of exploding rocket-propelled grenades echoed across Beirut into the night.

People huddled in hallways and stairwells as gunmen rushed from one street corner to the next firing at their foes. Some families fled to neighbourhoods that remained quiet.

'There is so much shooting and explosions outside. Our building is in the middle of the fighting,' a terrified Ms Ghada Helmi said.

Fighting began along Corniche Mazraa, an avenue separating Shi'ite and Sunni areas, then spread to other districts. Combat was heard near the office of Lebanon's Sunni spiritual leader, an ally of the government, and near the official residence of the opposition-aligned parliament speaker.

In peaceful neighbourhoods, people jammed into supermarkets rushing to stockpile food while outside gunmen armed with assault rifles and rocket propelled grenades (RPGs) peered from building entrances or took cover next to shuttered shops.

The unrest virtually shut down Lebanon's international airport for a second day and barricades closed major highways. Hizbollah first blocked roads in Beirut on Wednesday to enforce a strike called by labour unions, but confrontations quickly spread across the city.

Security officials said Thursday night that a mother and her son were killed when a grenade hit their apartment and two men were shot dead during the Beirut fighting. Eight people were wounded in the city and four more were wounded in a Sunni-Shi'ite gunbattle in the eastern Bekaa Valley, officials said.

Fighting intensified minutes after Hizbollah leader Hassan Nasrallah made a televised address charging that the government had declared war on his group when it decided this week to shut down Hizbollah's private telecommunications network.

He warned against trying to disarm Hizbollah and said his fighters would retaliate swiftly if attacked.

'Those who try to arrest us, we will arrest them. Those who shoot at us, we will shoot at them. The hand raised against us, we will cut it off,' Nasrallah said in a news conference via video link from his hiding place.

Later in the day, Sunni politician Saad Hariri made a televised appeal to Nasrallah seeking to calm the conflict.

'My appeal to you and to myself as well, the appeal of all Lebanon, is to stop the slide toward civil war, to stop the language of arms and lawlessness,' said Mr Hariri, son of former Prime Minister Rafik Hariri, who was assassinated in 2005.

Mr Hariri proposed a compromise, saying the decision on the Hizbollah communications network could be made by the army command rather than the Cabinet.

The military has sought to stay out of the feuding, fearing a repeat of its breakup in the long civil war that wracked this country - home to rival communities of Sunni and Shi'ite Muslims, various Christian sects and Druse.

Hizbollah's Al-Manar television and National Broadcasting Network (NBN TV) of parliament Speaker Nabih Berri said later that the opposition rejected Mr Hariri's offer.

Hizbollah views its private network of primitive phone lines as vital to its leaders' security. Nasrallah has said it helped his guerrillas fight Israel's army in the summer of 2006.

The street fighting is the latest turn in a test of wills between the Hizbollah-led opposition and the government of Prime Minister Fuad Saniora. The US-backed government has only a slim majority in parliament, and the two sides have been locked in a 17-month power struggle that has kept government at a standstill and blocked a presidential election.

Worry intensified that the conflict could degenerate into a wider and deadlier sectarian conflict, a fear made raw by memories of the 15-year civil war that killed 150,000 Lebanese and left wide swaths of Beirut in ruins.

The fight could have implications for the entire Middle East at a time when Sunni-Shi'ite tensions are high. The tensions are fuelled in part by the rivalry between predominantly Shi'ite Iran, which sponsors Hizbollah, and Sunni Arab countries like Saudi Arabia and Egypt.

Egypt, which backs Lebanon's government, said it would call an emergency meeting of Arab foreign ministers to discuss the crisis, according to a Foreign Ministry spokesman, Mr Hossam Zaki.

The UN Security Council urged Lebanon's parties to resolve their differences through dialogue.

The White House said Hizbollah needs to decide whether it wants to be a terrorist organization or a political party. 'They need to start playing a constructive role and stop their disruptive activities now,' Mr Gordon Johndroe, a spokesman for the National Security Council, said in a statement. -- AP