Libyan fighters in the western mountains say they don't have enough weapons to fight Gaddafi. They improvise by cannibalizing junked cars and scrap metal to make rocket launchers. (William Booth/The Washington Post)

From the street, the operation run by a former army engineer known to the Libyan rebels as Rambo looks like an ordinary auto repair shop. Inside, a dozen of Omar Said’s mechanics are busy turning pickup trucks into armored fighting vehicles, complete with aging anti-aircraft guns.

What the Libyan rebels lack, they scavenge. Popular now: a portable launcher for firing an old Russian S-5 air-to-surface rocket from your shoulder. Components: four feet of drain pipe and a trigger made from a hair dryer. Range: about 2 1 / 2 miles.

Sitting next to a cannibalized Volvo sedan are two confiscated Libyan army tanks. “They were broken,” said Takek Issa, a local fighter. “It took us only a day to get them running.”

Leaders of opposition forces fighting here along the ragged spine of western Libya’s Nafusa Mountains boast that they would be able to storm into the capital, Tripoli, in a matter of days — if only they had more, and bigger, weapons.

“Our problem is weapons. We need them, but we don’t have them,” said Col. Tarek Zanpou, who commands the 250 fighters in the Berber town of Kabaw. “Half of my men go into battle without a gun.”

Zanpou, a former intelligence officer in Libyan leader Moammar Gaddafi’s army, said the rebels have only the arms they seize from fleeing government forces. It has been impossible, he said, to bring weapons into the mountains because the Tunisian government won’t allow them to cross their border and forces loyal to Gaddafi control the roads on the other three sides.

Rebel commanders say that while they depend for their lives on the NATO warplanes that have grounded Gaddafi’s air force and helicopters, a lack of arms is crippling their ability to push the fight forward and end the five-month civil war.

The scarcity of guns was visible Wednesday when rebels battled troops loyal to Gaddafi around the contested town of al-Qualish.

Many of the rebels who jumped into pickup trucks to roar into battle carried nothing. Young men hitched rides from the rebel stronghold of Zintan to the front lines, hoping to grab a rifle from a retreating or captured soldier.

In the hillsides, opposition forces shot S-5 rockets at the Gaddafi troops from homemade launchers, with firing fuses ignited by car batteries and switches made from disassembled military radios.

Rebels say they aim their rockets by eyeball. An older soldier with the opposition, Moktar Zintani, said sometimes they use spotters with satellite phones to help find targets. “They say, ‘A little to the left, a little to the right,’ ” Zintani said.

At a rebel military headquarters, seized rockets, shells, flares and grenades filled old wooden crates. A soldier pointed out a box containing four brown tubes. He said, “We want to shoot that, but we don’t know what it is.”

Asked about their military training, a group of Berber rebels from the coastal town of Zuwarah answered, “Medal of Honor.” They explained it’s a first-person shooter video game popular on PlayStation.

Here, they are engaged in a game with deadly consequences. In the fighting Wednesday, at least eight rebels soldiers were killed and more than two dozen wounded, according to hospital workers in Zintan.

Although NATO enforces a no-fly zone over Libya, it appears to allow rebel flights that shuttle personnel, food, medicine — and allegedly some weapons and communications equipment — between rebels in the eastern city of Benghazi and a stretch of two-lane highway here in the west.

On Monday, two reporters watched a four-engine jet take off from the highway and climb quickly into the sky.

“It is true that there are not enough rifles for the fights. But we don’t need the Kalashnikovs so much. We need the guns that can fire these,” said Col. Muhammad Khabasha, holding up a large 50-caliber bullet.

“Gaddafi is a murderer,” said Khabasha, a rebel leader here who said he served for 34 years in the Libyan army before defecting this spring. “With this bullet, I would like to kill him.”