Filed at 6:41 a.m. ET

MOSCOW (AP) -- Formalizing restrictions that date back to Soviet times, the Russian government has issued a list of about 90 cities, towns and villages that are normally closed to outsiders for security reasons.

The order, signed by Prime Minister Mikhail Kasyanov, was published in the government daily Rossiyskaya Gazeta on Wednesday. Kasyanov said the order was intended to officially establish the names of the settlements.

The list includes the nuclear centers of Zheleznogorsk in Siberia and Snezhinsk in the Ural Mountains, the chemical center in Shikhany in the Volga River region, and the Arctic naval bases of Polyarny, Severomorsk and Vidyayevo.

All the sites on the list have been closed to visitors since Soviet times. But in the Soviet era, their residents often enjoyed high wages and other government privileges; now many are struggling for survival, with diminished government subsidies since the 1991 Soviet collapse.