Two US Navy Seals who went missing during an operation to seize Iranian weapons bound for Yemen’s Houthi rebels have been declared dead after a 10-day search failed to locate them, the US military has said.

US Central Command (Centcom) had previously said that two Seals who were reported as lost at sea were involved in the 11 January operation, in which the elite special operations personnel boarded a dhow off the coast of Somalia and seized missile components made in Iran.

“The search and rescue operation for the two Navy Seals reported missing during the boarding of an illicit dhow carrying Iranian advanced conventional weapons … concluded and we are now conducting recovery operations,” the statement said.

The US military said earlier that the Seals were lost while its naval forces were conducting a “flag verification” of a dhow near the coast of Somalia.

It said commandos based on the USS Lewis Puller, which is classed as an expeditionary mobile base vessel, executed a “complex” night-time boarding, with the support of helicopters and drones, and seized Iranian-made ballistic and cruise missiles components.

In November, Houthis began targeting ships in the Red Sea they claimed were linked to Israel – attacks they said were in support of Palestinians in Gaza, where Israeli forces are at war with Hamas.

The US and Britain carried out strikes on dozens of Houthi rebel targets earlier this month, and American forces have since hit a number of missiles that Washington says were ready to launch and posed a threat to both civilian and military vessels.