The rebels are now trained by American and Egyptian special forces in eastern Libya.

An unnamed rebel source related how he had undergone training in military techniques at a "secret facility" in eastern Libya.

Despite the withdrawal from the air, some accounts describe a growing US presence on the ground. In the east, which is largely free from the regime's control, one rebel fighter said he and his comrades have received specialized training from US and Egyptian forces, although the US has denied that claim.

More training in weapons use and tactics would be useful to the largely disorganised and untrained fighters, the majority of whom have never had any military experience.

The US Defence Department has denied the claim and said special forces are not training the Libyan rebels there or anywhere else.

On Sunday, Libya's rebels also admitted that a NATO air strike near Brega that killed at least 13 opposition fighters on Friday had been caused by a rebel firing an anti-aircraft gun into the sky during a NATO sortie in the area. The man had apparently been firing in celebration, since opposition forces had advanced into Brega, and a rebel spokesman apologised for the incident.

The aircrafts of the coalition have very difficult to identify the targets, because in fact the same vehicles are used by the forces of Kadhafi and the Libyan rebels.

The Libyan rebels do not have military training and cannot communicate with the coalition during the air strikes.