The Wall Street Journal on Saturday demanded the immediate release of Evan Gershkovich, a Moscow-based correspondent who was arrested by Russia's FSB security service on suspicion of spying.

"Evan's case is a vicious affront to a free press, and should spur outrage in all free people and governments throughout the world, the newspaper said in a statement on Twitter.

(Reporting by Maria Ponnezhath in Bengaluru; Editing by Daniel Wallis)