Tasnim Irans Embassy in Moscow advised Iranian citizens to refrain from traveling to Russias northern and southern regions, where the authorities are concerned about illegal border crossings.
The embassy issued a statement after a number of Iranian nationals encountered problems upon arrival in some Russian airports.
The statement warns Iranian citizens to avoid traveling to the northern and southern regions of Russia, where they may come under suspicion of planning to cross Russian borders illegally.
The embassy has also noted that carrying an entry visa alone is not enough for foreign nationals to visit Russia, noting that the Moscow government preserves the right to refuse travelers entry for insufficient documents or on suspicion of trying to use the Russian soil for migration.
The statement also deplored the unacceptable treatment of a number of Iranian citizens at a Moscow airport, saying the embassy has held several meetings with the Russian Foreign Ministry officials and sent a couple of letters of protest to voice objection to the treatment of Iranian travelers.
The Islamic Republics Embassy in Russia has always emphasized that Iranian nationals must be treated with respect and their rights must be protected, the statement added.
Under a 2016 agreement, Iranian tourists, in groups of 5 to 50 people, can travel to Russia without an entry visa for up to 15 days.
In November 2015, Iran and Russia clinched the agreement on simplifying visa requirements, during Russian President Vladimir Putins visit to Tehran. The accord took effect in February 2016.
In recent years, there has been a sharp rise in the number of Iranian tourists traveling to Russia, particularly to Moscow and Saint Petersburg.