The State Department said drone attacks and explosions have occurred near Ukraine’s border and in major Russian cities, including Moscow, Kazan and St. Petersburg.

According to the advisory, "US citizens are again advised and strenuously reminded not to travel to Russia."

The US Embassy in Russia advises US citizens to seek shelter during drone attacks and to avoid travel to Russia.

The State Department said drone attacks and explosions have occurred near Ukraine’s border and in major Russian cities, including Moscow, Kazan and St. Petersburg.