Dozens of rebel fighters pulled out of the area amid heavy shelling.

Libyan rebel forces have been losing ground for days, including the key oil port of Ras Lanuf on March 13

Meanwhile, the French government said it would speed up its efforts to persuade the international community to impose a no-fly zone over Libya.

Human Rights Watch said Libyan authorities had carried out a wave of "arbitrary arrests and forced disappearances" in the capital, Tripoli.