WASHINGTON (Reuters) - The United States and Britain are taking action against a network of people who targeted Iranian dissidents and opposition activists for assassination at Iran's direction, the U.S. Treasury Department said on Monday.

       The network is led by Iranian narcotics trafficker Naji Ibrahim Sharifi-Zindashti and directed by Iran's Ministry of Intelligence and Security (MOIS), Treasury said.

       The Treasury statement said Zindashti’s network has carried out assassinations and kidnappings across a number of jurisdictions, aiming to silence Tehran's perceived critics.

       "The Iranian regime’s continued efforts to target dissidents and activists demonstrate the regime’s deep insecurity and attempt to expand Iran’s domestic repression internationally," said Brian Nelson, Treasury's under secretary for terrorism and financial intelligence.

       Treasury said its action was being taken in conjunction with the unsealing of an indictment by the Justice Department and Federal Bureau of Investigation.

       (Reporting by Susan Heavey and Doina Chiacu; Editing by Chizu Nomiyama)