A pan-Arab newspaper said on Sunday that the al Qaeda organisation led by Osama bin Laden bought tactical nuclear weapons from Ukraine in 1998 and is storing them in safe places for possible use.
There was no independent corroboration of the report, which appeared in the newspaper al-Hayat under an Islamabad dateline and cited sources close to al Qaeda, which the United States blames for the attacks of September 11, 2001.
The newspaper said al Qaeda bought the weapons in suitcases in a deal arranged when Ukrainian scientists visited the Afghan city of Kandahar in 1998. The city was then a stronghold of the Taleban movement, which was allied with al Qaeda.
Al Qaeda would use the weapons only inside the United States or if the group faced a "crushing blow" which threatened its existence, such as the use of nuclear or chemical weapons against its fighters, the paper quoted its sources as saying.
Ukraine inherited nuclear weapons from the Soviet Union but in 1994 it agreed to send 1,900 nuclear warheads to Russia and sign up to the Nuclear non-proliferation Treaty.
After the Soviet Union broke up in 1991, a former Russian National Security Adviser, Alexander Lebed, said that up to 100 portable suitcase-sized bombs were unaccounted for. Moscow has denied such weapons existed.
Lebed said each one was equivalent to 1,000 tonnes of TNT and could kill as many as 100,000 people.