Lebanese troops have intensified their assault on the perimeter of a Palestinian refugee camp, demanding the surrender of Islamist militants inside.
Lebanon's leaders say the military has the backing of the public
A helicopter fired two missiles into Nahr al-Bared camp, backing up machine gun and cannon fire that had reportedly destroyed the militants' sniper posts.
Five soldiers have died since the latest assault began on Friday.
The 13-day confrontation between troops and militants has killed more than 100 people, many of them civilians.
The UN says about 25,000 of the camp's 31,000 original residents have fled. Aid agencies have called for a ceasefire to allow more civilians to leave.
The violence, which is taking place in the north of the country, near the city of Tripoli, is the worst internal fighting Lebanon has seen since the end of its civil war 17 years ago.
The Lebanese army is trying to dislodge Fatah al-Islam militants who have been besieged in the refugee camp since 20 May.
Dozens of army tanks and armoured vehicles have moved up to the edge of the camp.
Artillery and mortar fire has been hitting the camp and the army says it has seized several Fatah al-Islam positions.
A spokesman for the militants denied they were on the retreat.
"We will not surrender and we will fight until the last drop of blood," spokesman Abu Salim Taha told AFP news agency.
The militants are reported to have moved deeper into the camp, a maze of concrete buildings and narrow alleyways. The army said some of the militants were using civilians as human shields and called on the militants to surrender.
The Lebanese minister of state for parliamentary affairs, Michel Faraoun, told the BBC the government had given the military a "green light" to deal with the militants.
He also said mainstream Palestinian groups were backing the government's action against the militants.
Members of Lebanon's anti-Syrian cabinet have described Fatah al-Islam as a tool of Syrian intelligence. Damascus denies any links to the group.
On Wednesday, a Lebanese military magistrate charged 20 captured members of the militant group with terrorism.
The charges were related to the deaths of soldiers and civilians. If convicted, the suspects could face the death sentence.
Thousands of people have already fled the camp for shelter nearby
The militants say they will not surrender to what they call Zionist Americans and their loyalists.
The violence began on 20 May after security forces raided a building in Tripoli to arrest suspects in a bank robbery. Fatah al-Islam militants then attacked army posts at the entrances to the camp.
A large force of Lebanese troops hit back, bombarding the camp and storming a building on the outskirts of Tripoli.
There are 12 Palestinian refugee camps in Lebanon that were set up after the creation of Israel in 1948. Palestinian militants inside the camp carry weapons and the Lebanese army traditionally does not enter them.
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