A small settlement in the desert, Bir Al-Ghanam is also the closest point the fighters have come to Muammar Qaddafi’s stronghold in the capital, lending it a strategic role in the rebels’ six-month campaign to end Qaddafi’s rule.

Military commanders in the region said on Saturday they had seized control of Bir Al-Ghanam in an offensive in which four anti-Qaddafi fighters had died.

Taking the town — which lies on a highway leading north to the Mediterranean coast and on to Tripoli — would break weeks of stalemate during which rebels have been unable to make big advances despite NATO air strikes on government forces.

Libyan Prime Minister Al-Baghdadi Ali Al-Mahmoudi said on Sunday that the fighters, under NATO air cover, had seized Bir Al-Ghanam temporarily but they had been driven out by local volunteers and Libyan forces.

“This is exactly what happened in Bir Al-Ghanam, which is back in the hands of the honorable and brave local tribes ... and under the legitimate control of the government of Libya,” he told a news conference in Tripoli.

But a local commander rejected that version of events. “Qaddafi is a liar because Bir Al-Ghanam is under our control,” Col. Juma Ibrahim, a commander from the nearby town of Zintan, told Reuters. “We are still in the same position we were yesterday.”

He said that in the past 24 hours opposition forces had, in fact, pushed about 10 km (6 miles) northeast of Bir Al-Ghanam, and were now planning to push toward the coastal town of Zawiyah.

Zawiyah, which lies 50 km (30 miles) west of Tripoli, has been the scene of two uprisings which were smashed by Qaddafi’s security forces. A large contingent of the rebels fighting around Bir Al-Ghanam are from Zawiyah.

It was not immediately possible to verify independently who was in control of Bir Al-Ghanam.

Most analysts say that Qaddafi will eventually be forced to relinquish power if NATO states and their rebel allies maintain the pressure on him by starving him of weapons, fuel and cash and attacking his forces.

However, some alliance members are unsettled by how long the Libyan campaign is dragging on and how much it is costing, especially at a time of economic uncertainty. If NATO wavers, this could give Qaddafi an opportunity to hold on to power.

For now though, there is no sign of a let-up in the air campaign, led by French and British warplanes. A Reuters reporter in Tripoli said there were multiple strikes overnight in the southeast of the city.

After the initial explosions, there were smaller blasts on the ground and flames shooting into the air, suggesting that the target contained highly flammable material.

Potentially adding to pressure on Qaddafi, Tripoli has been experiencing power shortages in the past few days and these have been growing worse.

Libyan state television appealed on Sunday to people to conserve energy by switching off air conditioners in mosques and offices when they are not in use.

Some areas of the Libyan capital are getting as little as four hours of power a day, residents said.

Mohamed Abu Ajeela Rashid, a former Libyan health minister who is now a senior hospital doctor, said power was cut while he was performing surgery. He said he had to complete the operation by the light of his cell phone.

Libyan government officials have said the problems will be fixed within the next few days. They blame NATO for attacking electricity lines, but an official with the alliance denied there had been any such strikes.

In eastern Libya, where fighters and pro-Qaddafi forces are fighting along another front, rebel commanders said they were making a big push to capture the coastal oil town of Brega, about 780 km from Tripoli.

But they said progress was slow because Qaddafi’s forces had laid minefields around the town. Pope Benedict, giving his Sunday blessing from the papal summer residence of Castel Gandolfo near Rome, appealed for an end to violence in the Middle East.

“My thoughts also go to Libya, where the use of arms has not resolved the situation,” he said. “I urge the international organizations and those with political and military responsibilities to relaunch the search for a peace plan through talks and constructive dialogue.”