Russia has cautioned its citizens wanted by the United States not to visit countries that have an extradition treaty with Washington.
In an advisory on September 2, the Foreign Ministry said that "detentions of Russian citizens in various countries, at the request of U.S. law enforcement agencies for the purpose of their extradition and prosecution in the United States, have become frequent."
It said Russian citizens were "in fact kidnapped" and that legal proceedings against them were "of a biased character, based on shaky evidence, and clearly tilted toward conviction."
Extradition has often caused tensions between Moscow and Washington.
Disagreements have been particularly sharp in recent months over the case of Edward Snowden, the former U.S. intelligence contractor wanted by the United States for espionage but granted asylum in Russia.
Based on reporting by "The New York Times," ITAR-TASS, and Interfax