WASHINGTON (Reuters): The United States and Britain on Monday imposed sanctions on 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 U.S. Treasury in a statement accused the network of being directed by Iran’s Ministry of Intelligence and Security and put sanctions on 11 people connected to it, including Iranian narcotics trafficker Naji Ibrahim Sharifi-Zindashti, who it said is the leader.

The Treasury said Zindashti’s network had 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.

The Treasury action freezes any U.S. assets of those targeted and generally bars Americans from dealing with them.

In announcing the targets for the sanctions, the Treasury Department said that in 2021, the network recruited Canadian national and British Columbia-based Hells Angels Outlaw Motorcycle Group member Damion Patrick John Ryan to assassinate individuals in the United States who fled Iran.

Ryan also recruited Canadian national and Hells Angels affiliate Adam Richard Pearson to carry out the murders, Treasury said. Both are presently incarcerated abroad on unrelated criminal matters.

Also targeted were people involved in the assassination of Iranian cybersecurity official turned critic Mas’ud Vardanjani and British-Iranian dissident Saeed Karimian, Washington said.

Britain imposed sanctions on Iranian officials it said were involved in threats to kill journalists on British soil, and others it said were part of international criminal gangs linked to Iran.

The sanctions targeted seven individuals and one organization, Britain’s Foreign Office said.

The sanctioned Iranian officials are members of the Islamic Revolutionary Guard Corps (IRGC) Unit 840, which an ITV investigation in Britain said was involved in plots to assassinate two television presenters from news channel Iran International in Britain.