KABUL, Afghanistan -- Materials left behind in a compound used by Osama bin Laden's al-Qaida network -- including a booklet offering advice on how to survive a nuclear explosion -- suggest the terrorist group may have been trying to develop chemical arms and other unconventional weapons.
Foul-smelling liquids and charred papers covered with chemical formulas littered a makeshift laboratory in one al-Qaida building in the heart of Kabul. Maps, mines and computer manuals were found in others.
Homeland Security Director Tom Ridge said Thursday that the documents are consistent with bin Laden's statements saying he desired nuclear weaponry.
But papers found detailing how to make a nuclear device were "taken off the Internet some years ago" and could've been widely available to people other than the al-Qaida terrorists, he said.
U.S. officials have said that they had no information to suggest bin Laden has succeeded in gaining nuclear weapons.
But "we have to be prepared for all eventualities including a nuclear threat," Ridge said.
The Kabul compound appeared to have taken a direct hit from what northern alliance soldiers said was a U.S. rocket.
The Times of London newspaper reported Thursday that designs for nuclear weapons, bombs and missiles -- written in Arabic, German, Urdu and English -- were among the debris left behind.
"There are descriptions of how the detonation of TNT compresses plutonium into a critical mass, sparking a chain reaction, and ultimately a thermonuclear reaction," The Times said.
Papers, manuals found
Room after room was filled with papers, formulas and maps, some partially burned, some with handwritten Arabic notations. There was a yellowed page from an old issue of Plane and Pilot magazine -- a story titled "A Flight to Remember."
At the rear of the main house, one room contained mountains of papers, some from training manuals showing diagrams of weapons. An English-language book described how to use a recoilless rifle. Small, anti-personnel mines littered the floor of another room.
An alliance soldier in camouflage dress walked through three houses pointing out pieces of paper with formulas, handwritten diagrams, pictures of rockets and other weapons. In the basement of one house was what looked to be a laboratory.
In another house where the al-Qaida men resided, according to the soldier, four types of land mines were found.