New advances have led Libyan rebels to regain ground, on the oil port of Brega on Wednesday, after Gaddafi's forces retreated. They've recovered mostly desert terrain, lost, in a pell-mell retreat from superior government firepower the day before.

At the tiny outpost of al-Arbaeen, half way between the contested oil port of Brega and rebel stronghold Ajdabiyah, rebels returning from the front reported rocket duels close to the port.

Libyan rebels pushed back towards Brega on Wednesday, regaining mostly desert territory after retreating at least 40 kilometers on Tuesday.

But it was impossible to verify accounts that they were back close to sparsely populated Brega, which sprawls across about 25 kilometers.

The conflict in the east has reached stalemate with Western air power preventing Gaddafi from landing a knockout blow and the rebels' army unable to push closer towards Tripoli.

Fighting along the open desert road is extremely fluid and territory has been lost and won very quickly.

As rebels in pick-ups piled with weapons headed west from Ajdabiyah, anger has mounted over alleged lack of air strikes by NATO.

Rebels have accused NATO of being too slow to order air strikes, saying Gaddafi's forces have been allowed to slaughter civilians in the western city of Misrata.

NATO has countered that it has become harder to strike Gaddafi forces because they are disguising themselves in civilian clothes, hiding among the population and taking other measures to avoid allied strikes.

NATO says it will have to adjust the way it operates in Libya to keep up with changing tactics used by forces of Moummar Gaddafi.