KAREL JANICEK and WILLIAM J KOLE
BRATISLAVA

Three men arrested in an attempted sale of uranium were peddling material believed to be from the former Soviet Union, police said yesterday.

Officials claimed it was weapons-grade, suitable for a "dirty bomb".

First Slovak Police Vice President Michal Kopcik said the two Hungarians and a Ukrainian, who were arrested Wednesday afternoon in eastern Slovakia and Hungary, had just under half a kilogram, or about a pound, of uranium in powder form.

"It was possible to use it in various ways for terrorist attacks," Kopcik said. He added that investigators believed the uranium was suitable for a radiological "dirty bomb".

However, nuclear experts who were shown police photographs of radioactivity readings contended the material was probably not as dangerous as authorities believe.

"Uranium is not very radiotoxic," said David Albright, a former UN weapons inspector who is now president of the Institute for Science and International Security in Washington, DC.

Kopcik said investigators were still working to determine who ultimately was trying to buy the uranium, which the trio allegedly was selling for $1m (£500,000).

He said police had intelligence suggesting that the suspects - whose names were not released, but who are all men aged 40, 49 and 51 - originally had planned to close the deal sometime between Sunday and Wednesday of last week. One of the Hungarians had been living in Ukraine.

Police moved in when the sale did not occur as expected, he said.

Kopcik said three other suspects - including a Slovak national identified only as Eugen K - were detained in the neighbouring Czech Republic in mid-October for allegedly trying to sell fake radioactive materials. It was unclear to what degree, if any, they played a role in the thwarted uranium sale.

"According to initial findings, the material originated in the former Soviet republics," Kopcik said.

The arrests heightened long-standing concerns that Eastern Europe is serving as a source of radioactive material for terrorist weapons.

But Vitaly Fedchenko, a researcher with the Stockholm International Peace Research Institute, said people should not get the idea that the world is awash in easily obtainable bomb components.

"The danger is definitely there. But there's no reason to panic," he said. "Most of the buyers' out there are law enforcement agents. And not all of the materials out there are weapons grade."

Over the last several years, Ukrainian authorities have arrested more than a dozen people on suspicion of smuggling or purchasing radioactive materials.

Concerns about nuclear smuggling have generally been focused on Russia and countries of the former Soviet Union, where security at nuclear-related industries deteriorated after the 1991 Soviet collapse.-AP