Photos show Russian submarine, ships arrive in Cuba ahead of Caribbean military exercises

Russian sailors were seen standing on a nuclear-powered submarine as it entered Cuban waters Wednesday with three Russian naval ships.

The vessels are expected to stay in Havana through the weekend ahead of military exercises in the Caribbean in the coming weeks.

Photos taken in Havana showed the submarine, identified as the Kazan, cruising into the Cuban capital city's harbor about 100 miles southwest of Key West, Florida.