Libyan rebels are struggling to take advantage of the aerial shield provided by international forces protecting them against most of Muammar Gaddafi's heavy weaponry.
Government forces shelled rebels regrouping in the dunes outside a key eastern city, while their snipers and tanks roamed the last major opposition-held city in the west.
The military air campaign appears to have impaired Gaddafi's air defences and artillery and rescued the rebels from impending defeat.
But the opposition force, with more enthusiasm than discipline, has failed to exploit the gains.
The international alliance has also shown fractures as officials struggle to articulate an endgame. China and Russia, which abstained from the UN Security Council vote authorising the intervention, called for a ceasefire after a night when strikes hit Tripoli, destroying a military seaport in the capital.
In an address shown on Libyan state television, a defiant Muammar Gaddafi said: "In the short term, we'll beat them, in the long term, we'll beat them."
The Libyan leader was said to have delivered the message to supporters at his residential compound near the capital Tripoli which was hit by an allied cruise missile on Sunday.
Most of eastern Libya is in rebel hands but their forces have struggled to make headway on the ground. Ajdabiya, a city of 140,000 that is the gateway to the east, has been under siege for a week. Outside the city, a ragtag band of hundreds of fighters milled about, clutching mortars, grenades and assault rifles.
Some men clambered up pylons in the rolling sand dunes of the desert, squinting as they tried to see Col Gaddafi's forces inside the city. The group periodically came under artillery attacks, some men scattering and others holding their ground.
Heavy anti-aircraft fire was lighting up the skies over Tripoli on Tuesday night and the sound of loud explosions echoing through the Libyan capital after nightfall. The gunfire appeared to signal a fourth night of US and European air operations over Libya to enforce a no-fly zone.