The fighting had eased off by late Monday, but three soldiers were killed in an attack on an army post outside the Nahr al-Bared camp, raising the overall toll to 58.
"From outside it's very easy to condemn the Lebanese army and government for what they are doing against Fatah-al-Islam"
Rabih, Mansourieh El Metn, Lebanon
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Hospital and security sources said 30 soldiers, 17 fighters, 10 Palestinian civilians and one Lebanese civilian had been killed.
Lebanese troops bombarded positions held by the fighters accused of links to al-Qaeda and Syrian intelligence, with tanks and heavy artillery earlier on Monday, the second day of the bloodiest internal fighting since the 1975-1990 civil war.
But there were complaints that the shelling was affecting whole communities of Palestinians in the refugee camp in north Lebanon.
Al Jazeera's Zeina Khodr reported that 30,000 Palestinians living in Naher al-Bared were running out of food, water and medicines as the refugee camp remained virtually under siege.
Sultan Aboul Aynan, the Lebanon chief of the mainstream Fatah movement from which Fatah al-Islam splintered off, called for a halt to the army's bombardment, warning that Palestinian civilians were paying the price for the actions of "a gang of outlaws".
A temporary lull in fighting allowed the Red Cross to evacuate 17 people but doctors described seeing bodies strewn on the streets of Nahr al-Bared, which like all refugee camps in Lebanon remains outside the control of the government and in the hands of Palestinian factions.
Abu Salim Taha, a spokesman for Fatah al-Islam, said: "The army is not only opening fire on us. It is shelling blindly. If this continues, we will carry the battle outside the city of Tripoli."
The US president said on Monday that those trying to topple Lebanon's government "need to be reined in".
"Extremists that are trying to topple that young democracy need to be reined in. Certainly we abhor the violence where innocents die.
"And it's a sad state of affairs when you've got this young democracy in Lebanon being pressured by outside forces," George Bush said.
|The 10-kg bomb exploded in a carpark in the |
Sunni Muslim district of Verdun in Beirut [EPA]
Syria has denied accusations that it had links to Fatah al-Islam, and Bush stopped short of accusing Damascus of being involved in the conflict.
"I don't know about this particular incident. I'll be guarded on making accusations until I get better information, but I will tell you there's no doubt that Syria was deeply involved in Lebanon. There's no question they're still involved in Lebanon."
In the capital Beirut, a bomb rocked a shopping area in the mainly Sunni Muslim district of Verdun wounding at least seven people, including two young boys, security sources and witnesses said.
Police said the 10-kg bomb was placed under a car, setting ablaze several vehicles and damaging buildings.
A 63-year-old woman was killed and 10 people were wounded in an explosion in a Christian district of the Lebanese capital on Sunday night.
Some Lebanese intelligence officials have blamed Syria for backing Fatah al-Islam, saying it wanted to destabilise the Beirut government.
But Damascus saw the turmoil as a bid to prod the UN Security Council into setting up an international tribunal to try suspects in the murder of Rafiq al-Hariri, the former Lebanese prime minister, for which Syria has been widely blamed.
Syria's ambassador to the UN, Bashar Jaafari, has denied any ties between Damascus and Fatah al-Islam.
Officials from the main Palestinian factions in Lebanon - which deny any links with Fatah al-Islam – have offered Fouad Siniora, the prime minister, help in crushing the group.
Siniora's Western-backed government has been paralysed for months by feuding between pro- and anti-Syrian factions.