Libyan rebels say they have pushed back pro-government forces in Bir al-Ghanam, a strategic town about 80 kilometers southwest of Tripoli.

Opposition fighters said Saturday that forces loyal to leader Moammar Gadhafi had retreated following fierce clashes.

For months, rebel fighters have been trying to move closer to Tripoli by gaining control of towns west of the capital.

Meanwhile, fighting is underway in Zlitan as rebels continue their efforts to wrestle control of the western town from pro-government forces.

The al-Jazeera news channel said that opposition fighters repelled an offensive by pro-government forces on Saturday after an intense battle involving rockets and small arms.

Separately, the Libyan government said Saturday that a NATO airstrike on the port in Zlitan had caused damage.

In a separate development, Italy demanded NATO investigate whether an alliance warship ignored a distress call from a boat full of refugees trying to flee Libya.

Foreign Minister Franco Frattini said Friday Italy was also asking NATO to consider changing its mission to mandate alliance forces in the region rescue and protect migrants fleeing the conflict by sea.

Italian ships Thursday rescued around 370 refugees from a boat drifting near the Italian Mediterranean island of Lampedusa. Relief organizations say the migrants told of dozens of people who died of dehydration and exhaustion during the six days the rickety boat was on the water.

Reports in Italy say a NATO warship 50 kilometers away was informed of the situation earlier this week, but refused to come to the migrants aid.

But NATO says it only learned of the ship in distress on Thursday, from Italy.