The world community is warning people to avoid Lebanon and stay out of Tripoli as a fierce battle continues to rage between Islamists and Lebanese troops.

Lebanese soldiers attacked a Palestinian refugee camp for a second day on Monday. They targeted an Islamist group believed to have ties with al Qaeda.

Observers say this is some of the worst fighting in the tormented Middle Eastern country since the end of 1975 - 1990 civil wars. Up to 79 people may have died in the clashes over the past few days.

Soldiers used M-48 battle tanks to fire on the Nahr el-Bared refugee camp, located on Tripoli's outskirts. The camp is thought to be a refuge for militants planning attacks outside Lebanon.

The militants fired back with mortars and grenades. Both sides used machine guns, and civilians got goat in the crossfire.

Late Monday, residents reported an explosion in the predominately Muslim neighborhood of Verdun in Beirut. Television footage showed a burning car and at least one injured man.

Despite reports of a truce, gunfire could still be heard well into the night, news agencies reported.

On Sunday night, a bomb near a mall in the Christian sector of the capital killed a woman and wounded 12 other people.

The exact number of civilians killed during the fighting is unknown, however, Palestinian officials in the camp reported at least nine civilians were killed Monday and 40 people wounded.

A Lebanese official told The Associated Press that Saddam El-Hadjib, the fourth-highest ranking official in the Fatah Islam group, died in the fighting. He had been on trial in absentia in Lebanon, for his suspected role in a failed German terrorist attack.

Ahmed Methqal, a Muslim cleric in the camp, told Al-Jazeera that five civilians had been killed.

"You can say there is a massacre going on in the camp of children and women who have nothing to do with Fatah Islam," Methqal said.

"They are targeting buildings, with people in them. What's the guilt of children, women and the elderly?"

Emergency workers and security officials have not been able to gain access to the camp, which contains at least 30,000 residents, in order to access civilian casualties.

The State Department defended the Lebanese army, saying it was working in a "legitimate manner" against "provocations by violent extremists" operating in the camp.

"We strongly back the Lebanese army troops and what they are doing," Abed Attar, a resident of Tripoli who stood watching the tanks fire into the camp while others cheered, told AP.

Genesis of the crisis

The clashes are the latest boil in a festering political crisis.

Fatah al-Islam was immediately pegged by the Lebanese government as a front for Syrian intelligence.

Many Lebanese are uneasy with the presence of Palestinian refugees on their soil, and Palestinian leaders sought to distance themselves from the militants and side with Lebanon's army.

"The Palestinian people are not responsible," Hamas leader Osama Hamdan said as the Lebanese army tightened security in Palestinian areas across Lebanon.

Fatah al-Islam has only a few hundred fighters and little popular support. Many of the militants killed are from other Arab countries.

Despite that, one analyst thinks they could pose a significant security risk.

"This group could hold onto their position and their call on other groups in other camps other cities potentially and then the Lebanese army would be dragged into a full fledged confrontation with those extremist groups," said Walid Phares, author of Future Jihad.

A spokesman for Fatah al-Islam, Abu Salim, warned that if the army attacks did not cease, the Fatah fighters would intensify their attacks "and would take the battle outside Tripoli."

He did not elaborate on the threat, saying Fatah is only acting in self defense.

"It is a life-or-death battle. Their aim is to wipe out Fatah Islam. We will respond and we know how to respond," Salim told AP.

Sunday's flashpoint

The violence began Sunday with a gun battle in a Tripoli neighborhood. Police surrounded a militant-occupied apartment on a major road as part of efforts to track down suspects in a back robbery that occurred Saturday in Amyoun.

The militants were armed and resisted arrest by police, sparking a gun battle that spread to surrounding streets and continued on throughout the afternoon.

According to witnesses, the battle moved from the streets of Tripoli to the refugee camp where the militants seized Lebanese army positions at the entrance to the camp, reportedly capturing two armored carriers, and killing soldiers.

There were reports of smoke billowing from the camp as the Lebanese military targeted the militant positions inside the camp with artillery and heavy machine gun fire.

By midmorning, the military had brought reinforcements and was firing on militant positions, attempting to take back the checkpoints seized by the Fatah Islam fighters.