Members of Young Guard -- the youth wing of the ruling United Russia party -- came together outside the Church of Jesus Christ of Latter-day Saints' Russian headquarters in Moscow chanting slogans such as "No to foreign agents!," RIA Novosti reported.
"This is an American sect," said Ekaterina Stenyakina, co-chair of Young Guard's coordinating committee. "They are funded by the United States of America, and it's been proven that many young Mormons return to the U.S. to work for the CIA and FBI."
Experts say Russian authorities have long worried about Mormon church's influence in Russia.
"Because [Mormons] are involved in humanitarian activity, such as feeding the homeless or handing out literature, this is perceived as some form of bribery," religious expert Ivar Maksutov, a researcher at the Russian State University for the Humanities, told RIA Novosti recently.
Church officials denied the protesters' claims.
"It is somebody's opinion without any facts, without any legal investigation, without court decisions," Elena Nechiporova, director for the church's East Europe area's Public Affairs Department said, adding that "preaching the gospel is our main goal."