Lebanese troops and Islamist fighters have exchanged fire at a Palestinian refugee camp where dozens of people have been killed in recent clashes.
At least 11 people reportedly died in clashes over the weekend
Artillery shells struck the Nahr al-Bared camp, near the city of Tripoli, and militants replied with automatic weapon fire, reports said.
The army has been trying to crush the Fatah al-Islam faction since violence first flared on 20 May.
Some 3,000 civilians are still thought to be inside the camp.
An estimated 30,000 lived there before the violence began.
The latest gun battles flared after another violent weekend at Nahr al-Bared, which has been surrounded and bombarded by the Lebanese army for several weeks.
At least 11 people were reportedly killed in clashes over the weekend near entrances to the camp.
Split from Palestinian group Fatah al-Intifada in late 2006
Believed to have 150-200 armed men, based in Nahr al-Bared camp
Denies al-Qaeda links but says it endorses its ideas
Has links with Syrian intelligence, Lebanon says
Leader is Shaker al-Abssi
However, the Lebanese army has not entered Nahr al-Bared. There is a longstanding convention that the army does not go into Lebanon's 12 Palestinian refugee camps, leaving security inside to militant groups.
The current conflict with Fatah al-Islam erupted on 20 May when the Lebanese army tried to arrest a number of alleged members of the group.
There have been few signs of an end to the stand-off.
A group of clerics trying to broker a deal between Lebanon's government and the militants told the AFP news agency there was a "total impasse".
"The international leaders of the al-Qaeda network have taken over... and the Fatah al-Islam members are refusing to give up."
The violence is the worst internal fighting Lebanon has seen since the end of its civil war 17 years ago.
Lebanon is home to more than 350,000 Palestinian refugees, many of whom fled or were forced to leave their homes when Israel was created in 1948.