Fierce fighting erupted in and around a besieged Palestinian refugee camp in northern Lebanon on Monday as Lebanese troops resumed bombardment of Al Qaeda-inspired militants barricaded inside.

Troops, backed by heavy artillery and tank fire, blasted suspected hideouts of the Fatah Islam militants inside the Nahr el-Bared camp on the outskirts of the northern port city of Tripoli, as the battle against the militants entered its fifth week, witnesses said.

The intense bombardment sent thick black and white smoke billowing into the air and started fires in several shell-punctured buildings in the camp.

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In Sunday's clashes, troops entirely destroyed the militants' main headquarters located on the edge of the camp, according to the state-run National News Agency. But the whereabouts of Fatah Islam leader Shaker Youssef al-Absi and his top aides remain unknown.

After inspecting troops deployed around the Nahr el-Bared camp, Lebanese Army Commander Gen. Michel Suleiman said Sunday that the decision to eliminate the Fatah Islam militants was "final and irreversible."

"There is no other way out for these terrorists except to lay down their arms and surrender to justice before it is too late," Suleiman said in a statement carried by the NNA.

The fighting between Lebanese troops and Fatah Islam militants has claimed more than 150 lives — 69 soldiers, at least 60 Fatah Islam militants and more than 20 civilians — since its outbreak on May 20 — the worst internal violence to engulf Lebanon since the 1975-90 civil war.

A senior military official said Sunday there was "no time limit" for the army's plan to close in on the militants, but would not comment on a report from Lebanon's leading An-Nahar newspaper that said the military was close to winning the fight.

"The army is taking field measures to put an end to this abnormal situation," the military official said, speaking on condition of anonymity because he was not authorized to give official statements.

Mediation attempts by Palestinian factions and Islamic clerics to find a peaceful solution to the crisis have so far been unsuccessful.

The Western-backed Lebanese government insists that Fatah Islam militants surrender before the army stops its offensive. However, the group's leaders have pledged to fight to death.

The fierce combat underscored the tough task Lebanon's military is facing in its campaign to destroy the militants. But it is difficult to ascertain exactly what is happening inside the besieged camp since journalists have been kept out.

Most of the camp's 31,000 residents have fled since the fighting began, but the International Committee of the Red Cross has said that between 3,000 and 6,000 civilians remain behind.

The violence at Nahr el-Bared has threatened to spread to the country's 11 other Palestinian refugee camps. Two soldiers were killed in clashes earlier this month with militants in another Palestinian camp in southern Lebanon.

Fatah Islam emerged late last year after its leader and some 200 fighters split from the Fatah al-Intifada (Uprising), a pro-Syrian Palestinian faction based in Damascus.

In a separate incident Monday, an explosion went off in the Ein el-Hilweh refugee camp in southern Lebanon as members of an Islamic militant group tried to prepare a bomb, killing two people and wounding three, Lebanese security officials said.

Among those lightly wounded was a leader of the Jund al-Sham militant group, Shehadeh Jawhar, according to residents and Abu Sharif, the officials said.

The late afternoon blast ripped through a tire shop as some of the men were extracting TNT from a 107 mm shell, apparently to use it in making a bomb, the officials said on condition of anonymity because they are not authorized to speak to the press.

Residents said the two dead men were the shop owner — Jawhar's uncle — and another of the owner's nephews.

Also wounded was a Lebanese man named Mohammed Ghuneim, whose brother, Shadi, has been held for months in Saudi Arabia for suspected links with Al Qaeda, the security officials said.

Jund al-Sham, which is Arabic for Soldiers of al-Sham — an old Arabic word for the region of Syria, Lebanon and Jordan — is a splinter group from the Asbat al-Ansar group which also based in Ein el-Hilweh. Jund al-Sham's fighters battled Lebanese troops earlier this month, killing two soldiers.

Another group using the name Jund al-Sham has carried out attacks in Syria, seeking to topple its secular regime, but it is not known whether it is connected to the Ein el-Hilweh group.

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