Authorities in Moldova say they have detained six men and seized a quantity of enriched uranium.

The seized uranium can be used to arm nuclear weapons and is valued at nearly $29 million.

An interior ministry official said it came from Russia.

The six men are accused of trying to sell at least a kilo to a Muslim national from an unnamed African country.

"The container with uranium has been in Chisinau for a week," senior police investigator Vitalie Briceag told reporters.

"All that time, intermediaries were looking for buyers. The container, 20 centimetres long and 40 centimetres in diameter, was found at one of the detained men's apartments."

He said the metal was uranium-235, which can be used in nuclear weapons, although it was not clear to what degree it was enriched.

Four detainees were Moldovans and two were citizens of the unrecognised Transdniestria, a breakaway region of the former Moldavian Soviet republic.

"We have been helped by experts from Ukraine, Germany and the United States," Mr Briceag said.

"We have been following the suspects since March."

In August Moldova detained several men, some of them former police officers, who were trying to sell some uranium-238, an isotope that cannot be used in nuclear weapons.

- BBC/Reuters