SOUTH OF AJDABIYAH, Libya Packed to its limit with crates of artillery shells, the once-secret military base in the eastern Libyan desert is now open to anyone looking for an easy way to stock up on free ammunition.
Ringed by a minefield but otherwise abandoned, the facility was once heavily guarded by Muammar Gaddafi's troops until they fled when the site came under a NATO air strike earlier in the war.
With most of its bunkers still intact, the base near the rebel-held town of Ajdabiyah is now frequented by visitors of a different kind: from looters scavenging for scrap metal to potentially more shadowy characters.
Abandoned sites such as this are at the center of Western concerns that stockpiles of Libyan weapons and ammunition could fall into the wrong hands at a time when global trade in black market arms is thriving from Africa to Latin America.
Experts say that like dozens of other unsecured Libyan military bases, the site could attract militant groups and organized crime cartels. Rebels have tapped into the stockpiles as well, mainly to make improvised weapons for the frontline.
When Reuters visited the Ajdabiyah site this week, groups of men, their faces hidden underneath checkered turbans, were seen scuttling into the bunkers and selecting ammunition cases.
Kicking up clouds of dust, their pickup disappeared quickly out of sight, at least 10 tank shell boxes stacked up in the back of the truck. It was impossible to check who they were.
"No one is protecting these sites," said Fred Gras, a field manager with MAG, a non-profit organization working to clean up unexploded ordnance and secure sites such as this.
"It's tons and tons of stuff, boxes and boxes of ammunition. A lot of people come in, we see them all the time."
In one bunker, wooden boxes containing anti-tank artillery shells, manufactured in the Soviet Union in the 1970s, were stacked up in their hundreds. Some boxes were empty. Scraps of crumpled inventory lists were scattered on the dusty floor.
With the Libyan war dragging into a fifth month, U.S. officials say they are worried about reports of al Qaeda might be already smuggling arms out of Libya, and the U.S. State Department has raised its concerns with the Libyan rebels.
A Western official based in the region told Reuters one fear was that al Qaeda could gain access to plastic explosives from Libyan stockpiles. "It is definitely a worry," he said.
Another Western expert said al Qaeda's North African wing, al Qaeda in the Islamic Maghreb (AQIM), might have already have its eye on some of the stockpiles.
"There is definitely a risk that what is being picked up is not making its way to the frontline. This was a huge problem in Iraq and the looted ammunition was used extensively in IEDs (improvised explosive devices) as well as being found in other theatres," said the source who spoke to Reuters anonymously.
"No hard evidence yet but I have heard rumors that AQIM has some of the MANPADS (man-portable air-defense systems) already."
Much of the Gaddafi-era weaponry and ammunition originated from factories in Eastern Europe and Russia. At Ajdabiyah's 35-bunker facility alone, there were thousands of wooden boxes containing grenades, rockets, explosives and other ammunition.
U.S.-based Human Rights Watch has called on rebels to safeguard munitions depots in areas under its control.
"The arms depots may accidentally explode if munitions are carelessly moved," it said in April.
"The weapons could also pose direct dangers to civilians if used by untrained people, abusive rebel groups, or others willing to engage in terrorist attacks."
The rebel council in its coastal stronghold of Benghazi says it is doing everything in its power to secure sensitive sites, but, with its forces struggling to regain momentum against Gaddafi troops on several fronts, its priorities lie elsewhere.
"We are discussing what to do with ammunition stockpiles. We hope to use them," said one rebel source.
With its crumbling gates wide open and no questions asked, it is impossible to say for sure who the visitors are.
Some of them are believed to be the rebels themselves looking for ammunition they can use in improvised weapons. But rebels have no sophisticated weaponry and most larger-caliber ammunition stored at Gaddafi bunkers is of no use to them.
Civilians have also looted the site, scavenging for scrap metal, particularly copper, brass and aluminum - a valuable commodity at a time when wages are not paid and many families are struggling to make ends meet.
Others look for anti-vehicle mines to extract explosives to make homemade devices that are used widely by Benghazi fishermen to catch fish. Blasts from their fishing excursions into the Benghazi harbor often reverberate across the rebel stronghold.
For non-profit groups working to secure sites such as this, the main concern is the risk to civilians who blow themselves up regularly while picking through bits of ammunition.
Hundreds of people are believed to have been killed in such accidents since the start of the conflict in February.
Gras and his team work through ammunition sites to clear them of unexploded ordnance as part of a broader program coordinated by the United Nations.
"Someone from the (rebel) government has to decide what (can be done) with this," said Gras, as he pointed at endless rows of ammunition bunkers. "Maybe we need to destroy it so Gaddafi forces can't take it? Maybe it's for the next army? We have to wait and see."
(Additional reporting by Christian Lowe in Algiers; Writing by Maria Golovnina)