Yemen’s Houthi militants claimed they attacked two US ships in the Gulf of Aden on Monday. The group’s military spokesman Yahya Sarea said the operation was carried out with naval missiles and resulted in accurate and direct casualties. The UK Maritime Trade Operations (UKMTO) agency received a report of the incident and indicated that an investigation was ongoing. The decision to use unmanned “underwater vessels” by the Houthis presents a new danger, adding to their use of ballistic missiles, small watercraft, and helicopters in attacks on ships. There are concerns about deterring the group, as they are supported by Iran and are a key frontline force for the country. These attacks have led some shipping companies to avoid using the Red Sea shipping lane. Seth J. Frantzman contributed to this report.