Police in ex-Soviet Moldova have arrested six suspected traffickers in radioactive materials and seized Uranium-235 which can be used to make nuclear weapons, officials said on Wednesday.

"On Monday police arrested in Chisinau six people seeking a buyer for a small amount of uranium," the country's Prosecutor General, Vitalie Briceag, told AFP.

"The police have learnt that they had found a potential customer, a citizen of a Muslim country in Africa," he said.

An interior ministry spokesperson said one of the suspects was in possession of a small container of Uranium-235.

The Moldovan authorities received assistance from Germany, Ukraine and the United States in their investigation, the prosecutor said.

Uranium-235 can be used both to produce nuclear weapons and at nuclear power plants.

In August 2010, the Moldovan police seized a container with 1.8 kilogrammes (4.0 pounds) of highly-radioactive Uranium-238 and arrested a group of suspected traffickers who had sought to sell it for nine million euros (11 million dollars).

Since the fall of the Communist bloc, experts have issued repeated warnings about the trafficking risks posed by former Soviet republics such as Moldova, an impoverished nation bordering EU member Romania and Ukraine.