The Lebanese Army continued to shell this refugee camp just north of Tripoli on Monday in the second day of its fight against a shadowy Islamic faction known as Fatah al-Islam.
The violence, the worst internal strife since the 1975-90 civil war, began early Sunday when Palestinian militants stormed the entrance of the seaside camp, home to 40,000 refugees, and overran Army positions. At least 71 people have been killed.
Lebanon may be confronting a prolonged siege with the group, which some say is linked to Al Qaeda. But it is also facing a larger battle as its fragile government struggles to maintain power in the wake of last summer's war and battles an opposition movement led by Syrian-backed Hizbullah.
In divided Lebanon, many have contradictory views of the true identity of Fatah al-Islam, which declared its existence late last year when it split from Fatah al-Intifada, a pro-Damascus Palestinian faction, and seized two of its bases in the seaside Nahr al-Bared camp. Is it an affiliate of Al Qaeda or a tool of Syrian military intelligence – or both?
The Lebanese government has vowed to crush the group once and for all, but says it will continue to abide by a longstanding agreement that prevents the state from entering Lebanon's 12 established Palestinian refugee camps.
"We have hermetically sealed them inside Nahr al-Bared, and we will use political and popular means and the Army to get rid of Fatah al-Islam," says Marwan Hamade, minister of telecommunications and leading anti-Syrian politician.
Palestinian factions have offered their support for the government's moves and have undertaken precautions to prevent any fighting in other refugee camps.
Fatah al-Islam is viewed with deep suspicion by other more moderate Palestinian groups, which should help ensure that the violence in Nahr al-Bared remains localized, analysts say.
After members of the group stormed the Army posts on Sunday, other militants deployed in central Tripoli to assist allies, some wanted by the Lebanese authorities on suspicion of carrying out a bank robbery a day earlier in the coastal town of Amioun, south of Tripoli.
Hundreds of Army reinforcements converged on Tripoli as a series of street battles broke out with the heavily armed militants.
Further fraying the nerves of the Lebanese, a large bomb exploded in a car park in eastern Beirut, killing one woman and wounding 12 on Sunday.
The government and its supporters in the anti-Syrian March 14 alliance accuse Syria of triggering the upsurge of violence. They say it's a Syrian reaction to the imminent adoption by the United Nations Security Council of an international tribunal to judge the killers of Rafik Hariri, a former Lebanese prime minister whose murder in February 2005 is widely blamed on Damascus.
Syria has denied any involvement in Mr. Hariri's death.
The tribunal lies at the heart of the six-month political crisis in Lebanon that has left the country politically and economically deadlocked.
The creation of the tribunal, the result of an agreement between the UN and the Lebanese government, depended on the formal approval of the Lebanese parliament. But Nabih Berri, Lebanon's parliamentary speaker, has refused to have a parliamentary session to allow a vote to proceed. Last week, Prime Minister Fouad Siniora asked the UN Security Council to push the tribunal through. The UN Security Council can bypass Lebanese parliamentary approval by adopting the tribunal under Chapter 7 of the UN charter.
The government says it believes that once the tribunal is a fait accompli, the pro-Syrian Lebanese opposition will agree to resolve other outstanding issues.
"Some are worried that if the tribunal comes in then bad things will happen to the country," says Mohammed Chatah, senior adviser to Siniora. "But we take the view that decoupling the international tribunal from other strategic issues in Lebanon will allow for progress in resolving these other issues."
But that may be wishful thinking, analysts say, pointing to the violence in north Lebanon and the bomb attack in Beirut.
Anti-Syrian politicians maintain that Fatah al-Islam is composed of Al Qaeda-linked militants and is controlled by Syrian military intelligence to carry out destabilizing acts in Lebanon.
"Palestinian Islamist groups in Lebanon have always had ties to Syrian intelligence. Many of them were trained in Syria and fought in Iraq before coming to Lebanon," says Radwan al-Sayyed, a professor of Islamic law and an adviser to Mr. Siniora.
The group has been accused of a double bus bombing in the Christian town of Ain Alaq in February that left three people dead. It has also been accused of several bank robberies, including Saturday's robbery in Amioun.
The group's leader, Shaker al-Absi, told the New York Times in March he wanted to spread Al Qaeda's message and was training fighters in the camp. He was in custody in Syria until last fall but had been released.
Fatah al-Islam declared itself last year when it split from Fatah al-Intifada, a pro-Damascus Palestinian faction, and seized two of its bases in the Nahr al-Bared camp.
Mr. Absi, a veteran Palestinian fighter who fought in Iraq alongside Abu Musab al-Zarqawi, says the group has nothing to do with Syrian intelligence and is devoted to the Palestinian cause.
According to Islamist sources in Tripoli, the group is receiving funds from supporters in the city who belong to the austere Salafi branch of Sunni Islam. Fatah al-Islam has been using the funds to build a base of popular support in Nahr al-Bared by offering services, say sources.
"They marry widows or very poor women to give them a home. They are good people who follow an Islamic way of life," says Suleiman Abdullah, a sympathizer.
As for the claim that the group is linked to Al Qaeda, Sheikh Ibrahim Salih, a prominent Salafist cleric in Tripoli was dismissive.
"Al Qaeda is an ideology only. It is an ideology of opposition to America and Israel and to live an Islamic life," he says. "We all believe in that, therefore we are all Al Qaeda."