Economy Minister Sami Haddad told CNN on Monday night his army was battling "international terrorists" from the Sunni militant group Fatah al-Islam and that there was no friction between Sunnis and Shias in Lebanon.
But with the army continuing to fire heavy artillery into Nahr al-Bared camp, a square-kilometre slum housing over 40,000 Sunni Palestinian refugees, analysts are warning not of intra-Lebanese strife, but the prospect of the growing civilian casualties sparking a wider uprising across Lebanon's 12 Palestinian refugee camps and beyond.
"If this situation continues and the army continue to shell civilian areas in the camp, then we could see a domino effect across all of Lebanon's refugee camps and we could start a war between the Palestinians and the Lebanese," Amal Saad-Ghorayeb, visiting scholar at the Carnegie Middle East Centre in Beirut, told IRIN.
"Palestinian civilians had initially supported the Lebanese army's efforts in the camp against this foreign group. But now Fatah al-Islam is changing their discourse into fighting to protect Palestinian lives against the Lebanese army. The government has opened a Pandora's box of inter-related problems that it will not be able to contain," added Saad-Ghorayeb.
Under a decades-old Arab agreement, the Lebanese army does not enter any Palestinian camps, leaving security to the Palestinians themselves. So far in its campaign against Fatah al-Islam in Nahr al-Bared, the army has limited its fighting to the edges of the camp and to pounding with artillery and tank fire suspected Fatah al-Islam positions inside the camp.
Parliamentarian Ammar Houry, who is a member of the pro-Western ruling coalition and a close advisor to parliamentary majority leader Saad Hariri, told IRIN he believed the army would succeed in its mission.
"No problems between Palestinians and Lebanese"
"The government has taken the decision to finish Fatah al-Islam and that is what we will do," he said. "There are no problems between the Palestinians and the Lebanese."
A spokesman for Fatah al-Islam, which began as an offshoot of the Damascus-based Fatah Uprising, told IRIN during an interview in Nahr al-Bared before the outbreak of hostilities that the group draws its members from poor and disaffected youth living in the camp, but that it also has links to other radicals outside the camp.
In a statement to news organisations on Tuesday the group claimed responsibility for two bomb blasts that struck Christian and Sunni neighbourhoods of Beirut late in the evening over the past two days. It warned of further attacks in the capital.
"As the fighting rages against the Lebanese army in the area of Nahr al-Bared camp, a group of heroic mujahideen [holy warriors] has planted and blown up two explosive charges in the heart of Beirut," it said in a statement sent to foreign news agencies in Beirut.
"We have warned the Lebanese army, and we have now fulfilled our promise," the statement said.
"Our only relation is with God Almighty"
The statement denied reports linking Fatah al-Islam with other groups, such as al-Qaeda, and states, such as Syria, saying "our only relation is with God Almighty".
The government has accused Syria of sponsoring Fatah al-Islam in a bid to destabilise Lebanon as the country's divided leaders bicker over the formation of an international tribunal to try suspects in the 2005 assassination of former Prime Minister Rafik Hariri. A UN investigation has already implicated senior Syrian security officials and their Lebanese allies in the murder.
Damascus denies any link to Hariri's murder or Fatah al-Islam.
Fatah al-Islam's leader, Shakir al-Abssi, who is wanted on terrorism charges in Jordan and the US, was convicted on terrorism charges in Syria in the late 1990s but was released after serving just three years in jail for a crime that normally carries the death penalty or life imprisonment. Al-Abssi crossed into north Lebanon from Syria and established himself in Nahr al-Bared, where he is shielded from Lebanese authorities.
Hilal Khashan, professor of political science at the American University of Beirut, said the fact that Fatah al-Islam members had been arrested over suspected bank robberies suggested no one was necessarily bankrolling the group, although Syria was likely to have helped establish them in the camp.
Likely solution to crisis
Khashan said a likely solution to the crisis was a deal giving control of the camp to leading Palestinian factions in coordination with the Lebanese state, as happens in Ain al-Hilweh camp near the southern city of Sidon. Prime Minister Fouad Siniora met with Abbas Zaki, a member of Fatah's influential Central Committee, on Monday to discuss the issue.
"Fatah al-Islam will not leave but they'll be controlled and limited to the camp," said Khashan.
In an article in The New Yorker magazine earlier this year, respected investigative journalist Seymour Hersh accused the Sunni-dominated Lebanese government of funding the rise of Sunni militant groups in north Lebanon, as a bulwark against Shia Hezbollah - a charge the government denies.
For ordinary Lebanese, the escalating security breakdown in their country is a symptom of what they see as a wider malaise in Lebanese politics.
"All I want is to live safely, no matter who governs this country," said Naji Kamel, who saw her beauty salon in Beirut's Christian neighbourhood of Ashrafiyeh burn down after Sunday night's explosion, which killed one woman and injured a dozen bystanders.
"Why don't they unify their security efforts? Why don't the security forces work along with the army as one, not rivals? I'll tell you why: it's because this country simply lacks political agreement. What are they waiting for? For the country to be burned again?"