“Today’s action, taken in coordination with the Kingdom of Bahrain, underscores our collective commitment to disrupting Iran’s destabilizing forces and threats, particularly those which threaten our partners in the region and around the world,” Under Secretary of the Treasury for Terrorism and Financial Intelligence Brian Nelson said in a statement.

According to the Office of the Director of National Intelligence, Al Ashtar Brigades was founded in 2013 with the mission to overthrown Bahrain’s monarchy and has conducted at least 20 attacks in the country.

Treasury officials said several members of the militia fled Bahrain for Iran in 2018 to avoid serving terrorist-related prison sentences.

Among those blacklisted Tuesday include 34-year-old Hussein Ahmad ‘Abdallah Ahmad Hussein Al-Dammami, an accused financial facilitator of the terrorist organization.

U.S. officials said he was investigated in Bahrain on a slew of charges, including attempted murder and terrorism, and fled to Iran after he was sentenced to prison.

The other three hit with sanctions Tuesday were Iran-based Al-Ashtar Brigades members 32-year-old Ali Abdulnabi Ahmed Ebrahim M Alshofa, 33-year-old Hasan Ahmed Radhi Husain Sarhan and 42-year-old Isa Saleh Isa Mohamed Salman.

The sanctions — which freeze all property in their names and bar U.S. persons from doing business with them — come as the United States has sought to undermine Tehran’s influence in the Middle East amid Israel’s war against Iran-backed Hamas by targeting its proxy militias.

Iran’s Houthi militants have been attacking commercial as well as British and American warships transiting near the coast of Yemen since mid-November, and the United States has responded with sanctions and attacks of its own.

The Biden administration has said it seeks to de-escalate rising tensions in the Middle East but that it will defend itself from aggression.