“This is very unusual,” he responded on his Twitter account.
McFaul added that he could not recall similar reports, except for one instance "when our residence at Spaso House had a demonstration and we asked people to avoid the area."
Earlier, the US Embassy in Moscow, citing the media, warned American citizens about alleged "threats of terrorist attacks" in public places in Moscow and St. Petersburg, as well as in areas along the border of Russia and Ukraine.
The official representative of the Russian Foreign Ministry, Maria Zakharova, asked the American embassy for an explanation in connection with the publication on the website of the US embassy in Moscow of a warning about possible terrorist attacks in Russia.