LEBANON - May 21 - Lebanese Army Pounds Refugee Camp.

A bomb rocks Beirut for the second consecutive evening as the Lebanese army pounds a Palestinian refugee camp in northern Lebanon with tank and artillery fire in pursuit of Islamic militants. The army has been engaged in battles with members of the shadowy Fatah al-Islam group, which is using Nahr al-Bared camp on the outskirts of Tripoli as a base, since Sunday in the worst fighting in the north of the country since the end of the civil war in 1990. More than 70 people have been killed, including 27 soldiers. Fatah al-Islam spokesmen had earlier warned that it would take the fight outside of Tripoli if the army continued its bombardment of the camp, and the blast in west Beirut was seen as a message to authorities. On May 20 night a bomb exploded in a predominantly Christian neighbourhood of the capital, killing one. May 21 blast was thought to be the first of its kind in a Muslim neighbourhood. At least seven people were reported injured. May 20 clashes between the army and Fatah al-Islam were apparently triggered by raid on an apartment in Tripoli by security forces who were seeking suspects wanted in connection with a bank robbery. The militant group's fighters then mounted ambushes against soldiers around Nahr al-Bared camp and Tripoli. On May 21 the army laid siege to the camp while the militants fired at their positions. Lebanese officials regard the latest violence as part of attempts to hamper moves by the government to get the UN Security Council to set up a tribunal to try those suspected of the 2005 assassination of Rafiq Hariri, the former PM. A UN commission investigating the murder has yet to issue its findings, but progress reports have pointed the finger at top Syrian officials. Human rights workers warned the situation in the Nahr al-Bared camp, which holds more than 30,000 people, was dire, with little medical access or means of evacuation for civilians. The US state department on Monday said the Lebanese authorities were justified in their actions. "The Lebanese security forces are rightfully acting to enforce law and order in Lebanon", said spokesman SeanMcCormack. Ahmad Fatfat, the Lebanese youth and sports minister and former interior minister, told the FT that Fatah al-Islam was linked to Syrian intelligence. He said the group's swift response to the raid on the Tripoli apartment indicated it had been planning an attack against authorities with the motive of destabilising Lebanon. Damascus has denied any links to the group. "It's clear Fatah al-Islam was planning a big attack in the north", Fatfat said. "Our strategy is we cannot stop without solving this problem". Fouad Siniora, the PM, met Palestinian officials on May 21 and other government officials were working with Palestinian groups to resolve the issue while protecting civilians. The dilemma the government faces is how to root out the militants without killing ordinary residents. Under a long-standing agreement, the army is not allowed to enter the camps, which have become havens for criminal gangs and militant groups. There have also been suggestions that Fatah al-Islam has connections to al-Qaeda, but Fatfat said he had no information about that. Other Lebanese say little is known about the militants, adding that speculation about the fighting and the group's affiliations depends on people's political orientation. The country has been polarised between pro-Syrian opposition groups, led by Hizbullah, and western-backed, anti-Syrian parties in the government since the end of Hizbullah's war with Israel last year. Fatah al-Islam is said to have split off from the Fatah Intifadah, a pro-Syrian movement, last year. Fatfat said Fatah al-Islam's leader, Shaker al-Abssi - a Palestinian who was sentenced to death in Jordan in absentia for the 2002 killing of a US diplomat - was inside Nahr al-Bared camp and had been sent to Lebanon by Damascus. The group had 300 to 400 members, and included fighters from other Arab nations, he said.