CNN's Ben Wedeman and Ingrid Formanek reporting from Tripoli, Libya –

TRIPOLI, Libya (CNN) - A potent stash of Russian-made surface-to-air missiles is missing from a huge Tripoli weapons warehouse amid reports of weapons looting across war-torn Libya.

They are Grinch SA-24 shoulder-launched missiles, also known as Igla-S missiles, the equivalent of U.S.-made Stinger missiles.

A CNN team and Human Rights Watch found dozens of empty crates marked with packing lists and inventory numbers that identified the items as Igla-S surface-to-air missiles.

The list for one box, for example, written in English and Russian, said it had contained two missiles, with inventory number "Missile 9M342," and a power source, inventory number "Article 9B238."

Grinch SA-24s are designed to target front-line aircraft, helicopters, cruise missiles and drones. They can shoot down a plane flying as high as 11,000 feet and can travel 19,000 feet straight out.

Fighters aligned with the National Transitional Council and others swiped armaments from the storage facility, witnesses told Human Rights Watch. The warehouse is located near a base of the Khamis Brigade, a special forces unit in Gadhafi's military, in the southeastern part of the capital.

The warehouse contains mortars and artillery rounds, but there are empty crates for those items as well. There are also empty boxes for another surface-to-air missile, the SA-7.

Peter Bouckaert, Human Rights Watch emergencies director, told CNN he has seen the same pattern in armories looted elsewhere in Libya, noting that "in every city we arrive, the first thing to disappear are the surface-to-air missiles."

He said such missiles can fetch many thousands of dollars on the black market.

"We are talking about some 20,000 surface-to-air missiles in all of Libya, and I've seen cars packed with them." he said. "They could turn all of North Africa into a no-fly zone."

There was no immediate comment from NTC officials.

The lack of security at the weapons site raises concerns about stability in post-Gadhafi Libya and whether the new NTC leadership is doing enough to stop the weapons from getting into the wrong hands.

A NATO official, who asked to not be named because he was not authorized to speak publicly on the matter, said 575 surface-to-air missiles, radar systems and sites or storage facilities were hit by NATO airstrikes and either damaged or destroyed between March 31 and Saturday. He didn't elaborate on the specifics about the targets.

Gen. Carter Ham, chief of U.S. Africa Command, has said he's concerned about the proliferation of weapons, most notably the shoulder-fired surface-to-air missiles. He said there were about 20,000 in Libya when the international operation began earlier this year and many of them have not been accounted for.

"That's going to be a concern for some period of time," he said in April.

Gilles de Kerchove, the European Union counterterrorism coordinator, raised concerns Monday about the possibility that al Qaeda in the Islamic Maghreb, based in North Africa, could gain access to small arms, machine guns and surface-to-air missiles.

Western officials worry that weapons from the storage sites will end up in the hands of militants or adversaries like Iran.

The governments of neighboring Niger and Chad have both said that weapons from Libya are already being smuggled into their countries, and they are destined for al Qaeda. They include detonators and a plastic explosive called Semtex. Chad's president said they include SA-7 missiles.

An ethnic Tuareg leader in the northern Niger city of Agadez also said many weapons have come across the border. He said he and other Tuareg leaders are anxious about Gadhafi's Tuareg fighters returning home - with their weapons - and making common cause with al Qaeda cells in the region. Gadhafi's fighting forces have included mercenaries from other African nations.

The missing weapons also conjure fears of what happened in Iraq, where people grabbed scores of weapons when Saddam Hussein's regime was overthrown.

Bouckaert said one or two of the missing artillery rounds are "enough to make a car bomb."

"We should remember what happened in Iraq," he said, when the "country was turned upside down" by insurgents using such weaponry.

There have been similar concerns in Afghanistan, where the United States provided thousands of Stinger missiles to the Afghan mujahedeen when they were fighting the Soviets in the 1980s. The United States has spent hundreds of millions of dollars trying to buy them back, fearful that they would fall into the hands of terrorists.

CNN's Emily Smith, Tim Lister, Joe Sterling and Larry Shaughnessy contributed to this report