The action targets two Hong Kong- and Marshall Islands-based ship owners and two vessels for their role in shipping commodities on behalf of Sa'id al-Jamal, the Treasury Department said in a statement.

The revenue from the commodity sales supports the Houthis and their attacks against international shipping in the Red Sea and the Gulf of Aden, the department said.

Wednesday's action represented the latest bid by the U.S. to pressure the Iran-backed Houthi militant group over attacks in shipping. Last month, Washington imposed sanctions on oil tankers as well as two companies it accused of working with al-Jamal.

(Reporting by Ismail Shakil and Paul Grant; editing by Rami Ayyub)