Russian news reports say the Defense Ministry has information about the launch of "ballistic objects" fired from the central Mediterranean toward the eastern part of the sea.
News services in Russia quote a Defense Department official saying the early warning radar station in southern Russia detected the launches early Monday.
The reports said Defense Minister Sergei Shoigu had informed President Putin about the incident.
The United States is considering launching missiles at Syria to retaliate for an alleged chemical attack that took place August 21.
There were no reports of missile strikes.