Spokesman Dainis Mikelsons said several people had been detained in connection with the find.

"The control of radioactive substances is important in the light of the fight against international terrorism. Seizing them means averting threats to security of the state," he told AFP.

He said the radioactive material had been transferred to a radiation safety centre for identification but declined to disclose further details, saying he did not wish to undermine the ongoing investigation.

Mikelsons said the seizure was made possible by cooperation between the security police and a National Armed Forces special task force.

The press officer for Latvia's National Armed Forces, Uldis Davidovs, also declined to give details of the operation.

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