Nations typically issue travel warnings or alerts for citizens who face an array of threats abroad ranging from political unrest to natural disasters or health scares. The Russian Foreign Ministry, however, issued an advisory on Monday of a wholly different nature, urging citizens to check if U.S. authorities have a problem with them before they depart from Russia. The threat: the U.S. justice system.

“The incidents in which Russian citizens are detained in various countries of the world upon request of U.S. law enforcers who seek to extradite and prosecute them in the United States has increased,” the Foreign Ministry said in a statement on its website. “The last such cases were the arrests of Dmitry Ustinov in Lithuania, Dmitry Belorossov in Spain, Maksim Chukhrayev in Costa Rica and Aleksander Panin in the Dominican Republic.”

Ustinov is suspected of exporting military technology from the U.S. to Russia, Chukhrayev was wanted in connection with a money-laundering probe and Panin was charged with cybercrimes. It’s unclear on what grounds the U.S. wanted Belorossov.

“Experience shows that the judicial proceedings against those who were in fact kidnapped and taken to the U.S. are of a biased character, based on dubious evidence, and clearly tilted toward conviction,” the statement continued. “Russian embassies and consulates will, of course, offer consular and legal assistance to those in need, however one should not count on a successful outcome in such cases.”

Russia has previously lashed out at Washington for its extradition of Russian nationals from third-party states, in particular, the cases of Viktor Bout and K.V. Yaroshenko, who received sentences of 25 and 20 years, respectively. The Thai government arrested and extradited Bout (dubbed the “Merchant of Death” in U.S. media) in 2008 on charges of arms dealing, while Liberian officials detained Yaroshenko with the help of the U.S. Drug Enforcement Administration in Liberia for allegedly transporting thousands of kilograms of cocaine throughout South America, Africa and Europe.

Citing a worrisome trend, the Foreign Ministry recommended that all Russian citizens refrain from visiting the U.S. or any nations with mutual extradition treaties with the U.S. if they have “reasonable suspicions that U.S. law enforcement have any sort of claims against them.”

The subject of extradition has become an even greater issue of contention between the U.S. and Russia in recent months amid the case of Edward Snowden, the computer specialist accused of leaking secret National Security Agency documents who was granted temporary asylum in Russia. While the Obama administration calls for Snowden’s return, Russia has used the occasion to highlight numerous extradition requests of its own that officials in Washington have routinely ignored.

The two nations don't have any formal extradition treaty -- a fact that Russia made abundantly clear when it said it couldn't forcibly hand over Snowden from his hideaway in the transit zone of a Moscow airport.