Libyan militias prepare for fight against fast-approaching ISIS

MISRATAT, Libya --The Islamic State in Iraq and Syria (ISIS) took control of a power plant Tuesday in the Libyan city of Sirte. The terror group's presence has militias in Misrata -- up the coast from Sirte -- preparing to hold the line.

We met them in a Libyan workshop, resembling a scene from "Mad Max," where men recycle weapons for the fight against ISIS. Bullets are re-cartridged and a missile battery is split apart and repurposed.

The workshop manager, Sadun Langa, told us the heavy machine guns -- stripped from helicopters and tanks -- will be mounted on pick-up trucks for use by local militias battling ISIS.

Libyan workshop where men work to recycle weapons in anticipation of a fight against ISIS CBS News

Since the downfall of Libya's longtime dictator Muammar Gaddafi four years ago, the country has descended into a chaotic civil war. And in the lawlessness, ISIS has gained a foothold in towns and cities, including Sirte -- Gaddafi's former hometown.

A hundred miles of desert separates it from Langa and his men, who are determined to stop the extremists taking more territory.

"I will fight them," said Langa.

ISIS announced its arrival in Libya with trademark brutality in the form of two videos showing the beheadings of Christians. And from Libya's Mediterranean coast, ISIS vowed it would one day conquer Europe.

Sadun Langa, the manager of the Libyan workshop, examines damaged machine guns next to CBS News correspondent Holly Williams CBS News

ISIS won't be crossing the Mediterranean Sea anytime soon. A senior U.S. official told us that so far the group has fewer than 5,000 fighters in Libya. But ISIS has shown that it thrives on war and instability -- which makes Libya fertile ground.

Abdullah Al-Fortia commands a unit in western Libya's security forces and told us 80 percent of ISIS fighters have come from outside the country: From Mali, Tunisia, Sudan, Syria, and Egypt.

He says ISIS is a cancer and Libya the weakened body it's invaded.

"I don't like this type of people to live with us in Libya," he said. "They should go away. We don't want them to live in Libya."

Local militia leaders tell CBS News that ISIS advanced 20 miles Tuesday, seizing a power plant along the coast at Sirte. ISIS has been operating in Libya for under a year, but it is making rapid gains.