Four Lebanese soldiers have been killed in fighting with Islamist militants in the Nahr al-Bared Palestinian refugee camp in northern Lebanon.

A bomb killed three soldiers and a sniper shot dead another.

The army responded by shelling the militants, from the Fatah al-Islam group, who have been besieged at the camp for more than a month.

It is the second day of clashes since the Lebanese minister of defense declared the Islamist rebels defeated.

Defense Minister Elias Murr said on Thursday that leaders of Fatah al-Islam at the camp were on the run.

Mr Murr had told Lebanese TV the army had "crushed those terrorists", but that Lebanese troops were continuing their siege amid sporadic shelling and gunfire.

A month of fighting has left more than 170 people dead, in Lebanon's worst internal violence since the 1975-90 civil war.

'In hiding'

Nahr al-Bared, near the northern city of Tripoli, was home to 31,000 people before the fighting broke out. Approximately 2,000 refugees are still believed to be inside the camp.

Large parts of the camp have been left in ruins after a bitter struggle that began in late May when the Lebanese army tried to arrest a number of alleged members of Fatah al-Islam.

Lebanon has 12 refugee camps housing more than 350,000 Palestinians, many of whom fled or were forced to leave their homes when Israel was created in 1948.

There is a long-standing convention that Lebanon's army does not go into the camps, leaving security inside to militant groups.

The Lebanese government believes Fatah al-Islam is backed by Syrian intelligence, a claim Syria denies.

Syria has closed a border crossing in the north-east of Lebanon for "security" reasons.

Damascus closed two other crossings when fighting first broke out in the camp, also for safety reasons. Only the Masnaa crossing remains open.

PHOTO CAPTION

Smoke rises from Nahr al-Bared Palestinian refugee camp