The US Treasury Department has carved out exceptions to its new sanctions against the Houthis to allow humanitarian aid to continue to flow into Yemen.

The department’s Office of Foreign Assets Control has issued guidance that it said highlights that the sanctions against Ansar Allah, as the Houthi movement is officially known, are not intended to stand in the way of delivering supplies needed by the people of Yemen, who have been caught in a civil war since 2014.

“In particular, the shipping of commercial goods into ports and airports in Houthi-controlled areas, including transactions normally incident to such shipments … is not prohibited,” Treasury said, noting that port fees are among the exempt transactions.

The US Department of State announced on 17 January that it would redesignate the Iranian-backed Houthis after their forces, which control a large swathe of Yemen, began attacking shipping last year.

The designation came into effect last Friday, when Ofac added the group to its Specially Designated Global Terrorist list.

“Shipping and delivery of critical supplies to the Yemeni people can continue, in compliance with US sanctions,” wrote lawyers at Washington DC trade law firm Cassidy Levy Kent.

“In particular, the communique notes that the shipment of commercial goods into ports and airports in Houthi-controlled areas is not prohibited, and that commercial shipments of food and other commodities to the Yemeni people that were not prohibited prior to the designation of Ansar Allah are not covered by these new sanctions.”

The Treasury said nothing in a series of general licences for Yemen authorised shipments blocked under other sanctions programmes, particularly those against Iran.

The general licences authorise shipments of food, other agricultural commodities, medicine and medical devices, even in transactions involving Ansar Allah.

Also still allowed are refined petroleum products shipments involving the Houthis.

“Yemen is not subject to broad, jurisdiction-based sanctions. As a result, NGOs, international organisations and commercial businesses are not generally prohibited from importing humanitarian supplies into the country,” the Treasury said.

The Houthis do not appear likely to reciprocate.

A busy week of attacks in the Red Sea and Gulf of Aden has seen the militant group train its sights on bulkers used to transport agricultural products and tankers carrying refined oil products.