CNN's Ben Wedeman reported Thursday that his team had found two warehouses full of what appeared to be radioactive material on a military base near the Libya town of Sabha.

"We've come across two warehouses full of thousands of blue barrels -- some of them marked radioactive -- on the ground," Wedeman told CNN's Kyra Phillips. "In one of the warehouses, we found several large plastic bags full of what appears to be yellow powder, which had been closed also with this radioactive tape."

The team also found dosimeters and film that can be used to detect radiation.

"It was lightly guarded -- I stress the lightly -- by about three to four guys in their late teens, early 20s," he reported.

In a subsequent report, Wedeman described the materials as uranium yellow cake, a concentrated powder used in an intermediate step of manufacturing fuel for nuclear reactors and weapons-grade uranium.

"What it appears to be is yellow cake which is sort of one of the rudimentary -- is a uranium oxide compound that is one of the precursors which after a lot of refining can become radioactive material or nuclear material for a weapon," he explained.

"According to the International Atomic Energy Agency (IAEA), they are aware or were aware of this site, that it contained nuclear material or atomic material. In fact, we did find one piece of hand-written paper that said, '350,000 tons declared,' which would indicate that this is somehow what Libya's government in 2004 when it decided to come clean on its nuclear weapons program, declared that they possessed this material, this yellow cake."

Prior to the invasion of Iraq in 2002, President George W. Bush bolstered his case for war by making the false claim that then-Iraqi dictator Saddam Hussein had sought significant quantities of yellow cake from Africa.