Bani Walid remains a bastion of Moamer Gaddafi's forces but the Libyan desert town lacks the symbolic value of the ousted strongman's hometown Sirte and frustration is mounting among the besieging new regime fighters.

Orders from high command are to wait for the bigger prize.

"I want to fight but I am awaiting orders," said a young man at a mosque some 40 kilometres (25 miles) north of Bani Walid which serves as a base for forces loyal to the new regime's National Transitional Council.

NTC fighters have been stationed for weeks outside Bani Walid, a Saharan oasis 170 kilometres (100 miles) southeast of Tripoli.

But they say they are holding back until the fall of Sirte, which will free up fighters from Libya's third-largest city, Misrata for a full-on assault.

"The NTC told us -- do not enter Bani Walid immediately, encircle it and, once Sirte is freed in the current offensive, Misrata's fighters will come to help you," he said.

Under a heavy rain that turns the grains of desert sand into sticky clusters of dirt, out-of-work fighters kill their time by sipping coffee, their AK-47s and belt daggers readily at hand in case of action.

Others train by shooting mock targets.

Mohammed Swedan, 65, arrives from Tripoli on an old Japanese pick-up truck stocked up with medicine and food.

He believes Bani Walid is the most important battle still to be fought against the old regime.

The region's Warfalla tribe was the prime recruiting ground for elite units of Gaddafi's armed forces, and NTC commanders are convinced that Gaddafi's most prominent son, Seif al-Islam, is in the town, and possibly the former strongman himself.

"The fall of Sirte is a matter of days," the retired engineer said. "Bani Walid, I don't know, but Gaddafi's guys are going to lose here too, that's for certain."

The sense of frustration among the besieging NTC fighters is palpable.

"We need diesel for our tanks," one fighter says, angry that all the supplies are being sent to Sirte on the Mediterranean coast to the east.

Field commander Yusef al-Sharif insists that the campaign for Bani Walid is progressing.

"Gaddafi's men have left Bani Walid, they are fighting 10 kilometres (six miles) from the city centre," he said.

"We control 90 percent of the sector. We just have to push the pro-Gaddafi guys out of the outskirts and tackle the snipers."

With the offensive on hold, business is slow at the nearest field hospital to the front line. Medics treated a mere half dozen casualties on Saturday, Dr Hatim Omar al-Hossomi said.