Fatah Islam, the Islamic group beseiged by Lebanese troops near Tripoli, said Tuesday that it would cease firing in the latest attempt to bring a truce in three days of heavy fighting. At least two such attempts at a cease-fire have quickly fallen apart in the battle between the Lebanese military and the Fatah Islam group, whose fighters are holed up in the Nahr el-Bared refugee camp outside the northern port city of Tripoli. Fatah Islam will observe a cease-fire beginning at 2:30 p.m. (11:30 GMT) and expected it to hold "if the Lebanese army abides by it," spokesman Abu Salim Taha told The Associated Press from inside the camp. Earlier Tuesday, artillery and machine gun fire echoed around a crowded Palestinian refugee camp as the Lebanese government ordered the army to finish off the Fatah Islam militants. The fighting - which resumed for a third straight day after a brief nighttime lull - reflected the government's determination to pursue the Islamic militants who staged attacks on Lebanese troops on Sunday and Monday, killing 29 soldiers. Some 20 militants have also been killed, as well as an undetermined number of civilians. The Cabinet late Monday authorized the army to step up its campaign and "end the terrorist phenomenon that is alien to the values and nature of the Palestinian people," Information Minister Ghazi Aridi said. Hours after the decision, fighting flared up again Tuesday morning around the Nahr el-Bared camp outside the northern port city of Tripoli, with black smoke billowing from the area after artillery and machine gun exchanges. A spokesman for Fatah Islam, Abu Salim Taha, said fighters of the group repulsed several attempts by Lebanese troops to advance on their positions inside the camp. "The shelling is heavy, not only on our positions, but also on children and women. Destruction is all over," he said. Speaking to The Associated Press by telephone from the camp, he denied his group was behind bomb blasts in Beirut on Sunday and Monday night, as well as media reports the group's No. 2 was wounded. Inside the city of Tripoli, Lebanese troops moved in Tuesday against a suspected Fatah Islam hideout, witnesses said. Shots rang out on Mitein Street at midmorning, as security forces, acting on a tip about armed men in an apartment, raided the building using tear gas. At Nahr el-Bared, Lebanese artillery has pounded the suspected positions of the Fatah Islam, seeking to destroy the group with al-Qaida ties or force them out of the camp. The fighting has also raised fears that Lebanon's worst internal violence since the 1975-1990 civil war could spread in a country with an uneasy balancing act among various sects and factions. Fighting paused briefly Monday afternoon to allow the evacuation of 18 wounded civilians, according to Saleh Badran, an official with the Palestinian Red Crescent Society. Palestinian refugees have been hiding in their homes inside the camp and Palestinian officials there said nine civilians were killed Monday. Reports from the camp of food and medical supplies running out could not be confirmed because officials and reporters could not enter. Mufti Salim Lababidi, a Sunni spiritual leader of Palestinians in Lebanon, denounced the shelling which he claimed has killed or wounded some 100 civilians. "We have condemned the attacks on the army but what about the civilians being killed? Who is for those innocent people," he said on al-Jazeera television. "There are thousand ways to uproot Fatah Islam ... there are ways other than this." As he spoke, major Palestinian faction leaders met with Prime Minister Fuad Saniora for the second time in as many days to try to resolve the crisis. The camp is home to more than 31,000 people living in two- or three-story white buildings on densely packed narrow streets. It is one of more than 12 impoverished camps housing more than 215,000 refugees, out of a total of 400,000 Palestinians here. Lebanese authorities do not enter the camps, according to a nearly 40-year-old agreement with the Palestinians. Major Palestinian factions have distanced themselves from Fatah Islam, which arose here last year and touts itself as a Palestinian liberation movement. But many view it as a nascent branch of al-Qaida-style terrorism with ambitions of carrying out attacks around the region. The military assault adds yet another dimension to Lebanon's potentially explosive politics. Saniora's government already faces a domestic political crisis, with the opposition led by Iranian- and Syrian-backed Hezbollah demanding its removal. Raising fears of spreading violence, an explosion went off in a shopping area in a Sunni Muslim sector of Beirut late Monday, wrecking parked cars and injuring seven people - a day after a bomb blast in a Christian part of the capital killed a woman. The confluence of two bombings while the fighting was going on in Tripoli was highly unusual. Saniora also risks a backlash among Palestinians in Lebanon's other refugee camps, where armed groups and Islamic extremists have been growing in influence. The White House said it supports Saniora's efforts to deal with the fighting, and the State Department defended the Lebanese army, saying it was working in a "legitimate manner" against "provocations by violent extremists" operating in the camp. The leader of Fatah Islam, Palestinian Shaker al-Absi, has been linked to the former head of al-Qaida in Iraq and is accused in the 2002 assassination of a US diplomat in Jordan. He moved into Nahr el-Bared last fall after being expelled from Syria, where he was in custody. Since then, he is believed to have recruited about 100 fighters, including militants from Saudi Arabia, Yemen and other Arab countries, and he has said he follows the ideology of al-Qaida leader Osama bin Laden. Among the militants killed in the fighting Sunday was a man suspected in a plot to bomb trains in Germany last year, according to Lebanese security officials. Beirut security officials accuse Syria of backing Fatah Islam to disrupt Lebanon, charges that are denied by Damascus, which controlled Lebanon until 2005 when its troops were forced to withdraw from the country following the assassination of former Lebanese prime minister Rafik Hariri.