Lebanese Prime minister Fouad Seniora said on Saturday that Fatah al-Islam militants have but one choice, which is to surrender themselves to the Lebanese army and face justice.

The "terrorist gang" have to surrender themselves and their arms, Seniora said in an interview with Dubai-based al-Arabiya television on Saturday.

The premier, meanwhile, promised the militants "a fair trial" if they give up.

The army was carrying out missions against the Nahr al-Bared camp "like surgical operations in order to eradicate this phenomenon," he added.

Seniora noted that the Nahr al-Bared camp's population had fallen from more than 31,000 to less than 3,000, including some250 Fatah al-Islam militants, after civilians fled there after a truce established on May 22.

He accused the militant group of preventing the remaining civilians from leaving in a bid to use them as human shields.

Fierce battles continue between the army and the militants on Saturday. According to local Ya Libnan website, most of the militants have retreated and are now concentrated in a one-square km area, known as the "resistance square."

The army have surrounded the area and cut off supplies to the militants while kept pounding the militants there with heavy artillery, said the report.

Before Seniora made the latest warning, Abu Salim Taha, Fatah al-Islam spokesman inside the camp had said his group would never give up.

The army in the afternoon confirmed having lost six soldiers since Friday's resumption of heavy fighting with the militants, but the toll of the militants could not be verified.

The Lebanese army have been fighting with Fatah al-Islam militants at the Nahr al-Bared camp since May 20, which had leftover 80 dead before Friday's resumption of heavy fighting.