The US on Friday issued sanctions targeting commodity shipments financing Iran's IRGC-Quds Force and Houthis as Washington stepped up pressure on Iran’s proxy in Yemen.

The US Treasury Department said in a statement that 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 Treasury said it imposed sanctions on a Hong Kong-based company and a United Arab Emirates-based company shipping Iranian commodities on behalf of the network of a Quds Force-backed Houthi financial facilitator already under US sanctions. It also targeted four oil tankers.

The Treasury said one of the tankers, owned by Hong Kong-based Cielo Maritime Ltd, has shipped Iranian commodities to China on behalf of the facilitator, Sa’id al-Jamal. Another of the tankers sought to disguise the origin of the goods using forged documents, the Treasury said.

The sanctions come after US and British warplanes, ships and submarines launched dozens of air strikes across Yemen overnight in retaliation against Houthi forces for attacks on Red Sea shipping.

“The United States continues to take action against the illicit Iranian financial networks that fund the Houthis and facilitate their attacks,” the Treasury's Under Secretary for Terrorism and Financial Intelligence, Brian Nelson, said.

“Together with our allies and partners, we will take all available measures to stop the destabilizing activities of the Houthis and their threats to global commerce."

The Houthis have been attacking shipping lanes at the mouth of the Red Sea, where 15% of the world's seaborne trade passes between Europe and Asia.

The US has also accused Iran of being involved operationally in the Houthi attacks, providing military capabilities and intelligence to carry them out.

(Reporting by Reuters)