Yemen’s Houthi rebel group has issued formal warnings to 64 global shipowners, signalling a new phase in its campaign against Red Sea shipping.

The notices, described as “pre‑penalty” warnings, accused the targeted shipowners of violating a self-proclaimed blockade of Israeli ports, stating that these fleets are now “prohibited from transiting the Red Sea, Bab al-Mandab Strait, Gulf of Aden, and Arabian Sea,” and may be attacked “wherever they fall within reach”. 

This comes one month after the Houthis sank two Greek-owned bulk carriers, Magic Seas and Eternity C, leading the international Combined Maritime Task Force (CMT) to classify the threat level to Israel-linked shipping as critical and the overall risk to shipping as severe.

The Houthis have not revealed the names of the 64 shipowners yet, who risk seeing their insurance bills leap if their identities are made known.

Since November 2023, the Houthis have attacked dozens of merchant ships in the Red Sea, actions that NGO Human Rights Watch has found to constitute war crimes.

A joint statement from the International Chamber of Shipping, BIMCO, INTERTANKO, INTERCARGO, and the European Community of Shipowner Associations described the attacks last month as “callous”, urging global stakeholders to protect seafarers and uphold the freedom of navigation in this vital sea lane.

Arsenio Dominguez, the secretary-general of the International Maritime Organisation, has also voiced grave concern, emphasising the need for urgent multilateral action to ensure maritime security.