WASHINGTON (Reuters) – The United States on Tuesday imposed sanctions on companies it accused of being involved in the production of or transfer to Russia of Iranian drones that have been used in attacks on civilian infrastructure in Ukraine.

The U.S. Treasury Department in a statement said it imposed sanctions on the Shahed Aviation Industries Research Center, accusing it of being responsible for the design and production of Shahed-series drones being used by Russian forces in Ukraine, as well as other companies.

Russia has managed to procure drones from Iran that have been used to attack cities and power infrastructure in Ukraine. Iranian military entities and industries are already under heavy U.S. sanctions over Tehran’s nuclear development program

“As we have demonstrated repeatedly, the United States is determined to sanction people and companies, no matter where they are located, that support Russia’s unjustified invasion of Ukraine,” Treasury Secretary Janet Yellen said in the statement.

“Today’s action exposes and holds accountable companies and individuals that have enabled Russia’s use of Iranian-built UAVs to brutalize Ukrainian civilians,” she said, using the acronym for unmanned aerial vehicle.

Private military company Wagner group, Iran’s Islamic Revolutionary Guard Corps Aerospace Force, and Qods Aviation Industries – already under U.S. sanctions – were also designated by the State Department in Tuesday’s move, the Treasury said.

(Reporting by Daphne Psaledakis and Chris Gallagher; editing by Jonathan Oatis)