MOSCOW, February 21. /TASS/. The U.S. Embassy to Russia has explained its security alert for U.S. nationals in view of potential attacks on public spaces, in particular in Moscow and St. Petersburg, by media reports on bomb threats.

"In recent days a number of Russian media outlets have reported on a spate of bomb threats being made against Russian public buildings, including metro stations, in Moscow, St. Petersburg, and elsewhere. The U.S. Department of State has no greater responsibility than the safety and security of U.S. citizens overseas. Out of an abundance of caution, and in line with our commitment to providing U.S. citizens with clear and timely information so they can make informed travel decisions, we published this Alert," the embassy said.

It was reported on February 17 that an unidentified malefactor had sent alerts about bombs planted in Moscow at all shopping malls, courts and stations. Emergencies services checked the reports, finding no bombs at the sites.

On February 20, the U.S. Embassy issued a warning for its nationals over the alleged threat of terrorist attacks at public spaces in Moscow and St. Petersburg, as well as in the areas along the border of Russia and Ukraine. In their comments on the story on the embassy’s Twitter page, U.S. nationals expressed doubts as to the reliability of the media sources.

Russian Foreign Ministry Spokeswoman Maria Zakharova asked the U.S. embassy in Russia if they had passed to their Russian colleagues the data about allegedly existing threats of terrorist attacks in Moscow and St. Petersburg as well as along the Russian-Ukrainian border.