Forces loyal to Muammar Gaddafi have cut electricity supplies to much of the Western Mountains, threatening water supplies and stepping up a war of attrition with rebels who hold the plateau.
The blackout, which began five days ago, has coincided with an increase in shelling of the rebel command centre of Zintan and the town of Arrujban.
A Reuters reporter in Zintan heard about a dozen rockets strike the outskirts of the town on Sunday. He said they did not appear to have landed in a populated area and there were no reports of casualties, Reuters reports.
Rebels are scrambling to bring in generators through the border crossing they hold with Tunisia to restore wells that supply most of the water to this arid region. Temperatures have soared with the onset of summer.
The electricity stations lie in the desert plains, where pro-Gaddafi forces are positioned.
At night, Zintan is bathed in darkness, but lights are on in the nearby Gaddafi-held village of Ryayna.
Some Gaddafi positions are near the electricity stations themselves, possibly to dissuade NATO from bombing for fear of damaging the power supply.
“Because of the power cuts, we can’t pump the water,” said Abu Bakr, a senior rebel in Arrujban. “The wells are too deep to pump manually.”
He said rebels were working to bring a large generator from neighbouring Tunisia to pump water from the main well, known as Khartoum, which supplies Arrujban.
There are water reserves in tanks, he said, that could last another 10 days. The town has two large generators, one of which is supplying power to the medical clinic.
The western front of the Libyan war amounts to a chain of towns running more than 200 km (125 miles) from the Tunisian border across the bleak mountain plateau to Zintan, some 150 km southwest of the Libyan capital.
Gaddafi’s forces hold the desert plains and, at their closest point, are level with Zintan in Ryayna, some 10-15 km from the town centre.
With their planes grounded by NATO, forces loyal to Gaddafi are struggling to retake the high ground from the rebels. But the rebels’ isolation, and their limited means to resupply through the Tunisian border, will work against them the longer the conflict drags on.
Rebels have cleared a stretch of the main rebel-held road as a landing strip, saying they hope NATO will give clearance for aid and possibly weapons to be flown in from the de facto rebel capital Benghazi in eastern Libya.
“We have informed Benghazi and Benghazi should have informed NATO but still no reply yet,” said Colonel Juma Ibrahim, a senior rebel in Zintan.
He said he feared an imminent attack by forces loyal to Gaddafi. “They are preparing for something, this is the time,” he said. “We are asking Benghazi to supply us with weapons.”
Rebels in Arrujban say pro-Gaddafi forces some 20 km away in the plains have stepped up late-night shelling over the past five days. Similarly in Zintan, the town centre has been hit by rockets at least four times over the past week, forcing the evacuation of medical aid agency Doctors Without Borders.
Supplies of humanitarian aid are limited. Fuel is running low, meaning fewer people can afford to make the long journey to Tunisia to import supplies.
Abu Bakr said farmers were struggling to feed their sheep because much of the grazing land is located beyond rebel control, and had taken to selling their herds in Tunisia.
On Saturday in Arrujban, at a make-shift stall on the back of a van, buyers were rationed to 2 kg (4 pounds) of each type of vegetable per family. Fuel is limited to around 20 litres per person every two weeks.
“Because of the nature of the mountain, we are used to a hard life,” said Arrujban resident Mohammad Nwair. “We can adapt to difficult conditions.”