Two of the exchange houses are based in Yemen and one is in Turkey, the US Treasury Department said in a statement announcing the new measures.

“Today’s action underscores our resolve to restrict the illicit flow of funds to the Houthis, who continue to conduct dangerous attacks on international shipping and risk further destabilizing the region,” Under Secretary of the Treasury for Terrorism and Financial Intelligence Brian Nelson said in the statement.

The sanctions freeze any US assets belonging to the targeted entities and generally prohibit Americans from doing business with them.

The Houthis have seized or attacked with drones and missiles a dozen ships in the Red Sea and Gulf of Aden since November 19. They aim to raise the international costs of Israel’s offensive in Gaza, which was triggered by the October 7 onslaught into Israel by the enclave’s ruling Hamas militants.

US, British and French warships have shot down drones and missiles launched by the Houthis, who control huge swaths of Yemen captured during years of civil war. The Iran-aligned militia says it will continue the attacks in response to the Israeli assault on Gaza.

The US is leading a new naval task force to protect commercial shipping and has accused Iran of supplying weapons, financing, targeting and other assistance to the Houthis. Iran denies the allegation.

The sanctions announced by the Treasury on Thursday were the latest aimed at throttling the flow of alleged Iranian financing to the Houthis.

The Treasury said the measures targeted a network through which an Iran-based financier, Said al-Jamal, who has been under US sanctions since at least June 2021, provides Iranian funds to the Houthis.

Those hit included Al Aman Kargo Ithalat Ve Nakliyat Limited Sirketi, which the Treasury described as a “waypoint” for funding provided to the Houthis by Iran’s Islamic Revolutionary Guard Corps (IRGC).

Also targeted were Sanaa-based Nabco Money Exchange and Remittance Co, a recipient of funds sent by the Turkish entity, and its top official, Nabil Ali Ahmed al-Hadha, also president of the Currency Exchangers Association, the Treasury said.

Houthi-run Al Rawda Exchange and Money Transfers Co also was targeted for converting into Yemeni rials funds sent through Hadha’s accounts in Turkey, it said.

The targeted entities could not immediately be reached for comment.