Libyan rebels fled east under heavy rocket fire from leader Muammar Gaddafi's forces in the oil town of Brega on Tuesday in a sixth day of fighting that has failed to give either side the upper hand.

Pounding and machinegun fire was heard in the west of the sparsely populated desert settlement before rockets landed near a group of rebels waiting with machinegun mounted pick-up trucks at the town's eastern gate.

Rockets zipped back towards Brega from a rebel position near the entrance to its eastern residential zone.

Nearby, the remains of two trucks mounted with heavy machineguns lay smouldering, their burning tyres giving off a cloud of acrid smoke. Rebels said the trucks were hit by an air strike.

Scores of rebels leapt into their pick-ups and sped off, not stopping until they were more than 5 km (3 miles) east of the town limits.

A familiar pattern has set in, with lightly-armed volunteers pulling back under rocket fire. The better-trained rebel soldiers, most from army units that defected from Gaddafi or came out of retirement, tend to hold their ground.

The sustained burst of rocket fire appeared to give the Gaddafi forces the upper hand.

But each day has ended with no clear outcome, with clashes continuing around Brega's university and in the west of town near the Sirte Oil Company's facilities.

"It's back and forth," said rebel officer who did not give his name. "The clashes are continuing between the industrial area, the company and the residential area."

Rebels have shown better organisation than in past weeks, keeping territory for longer and forcing untrained volunteers to hold back as more experienced forces attack Gaddafi's front line troops.

The rebels had raced west to beyond Bin Jawad, about 525 km (330 miles) east of Tripoli, backed by Western air strikes early last week before Gaddafi's troops mounted a counter-offensive.

The rebels were then pushed back, just as rapidly, more than 200 km into the eastern half of the country before regrouping and holding their ground in Brega. – Reuters