The two US Navy SEALs who went missing during a night mission off the coast of Somalia on January 11 have died, US Central Command said. Announce Sunday.

The SEALs were on an interdiction mission, climbing over the side of the ship when one of them fell into the water. The second seal came after him. Central Command said that after an “exhaustive” search that lasted 10 days, they were not found.

“We mourn the loss of two of our Navy SEALs, and will forever honor their sacrifice and example. Our prayers are with the families and friends of the SEALs, the U.S. Navy and the entire Special Operations community during this time,” Gen. Michael Corella said in a statement.

The SEALs mission saw the elite unit deployed to intercept a sailboat heading to Yemen. The team found Iranian missile parts that were scheduled to be delivered to Houthi militants in Yemen, the group that for weeks has been firing on civilian and military ships in the Red Sea.

The ship sank and its crew was captured by special forces. This operation represents an escalation against Iran in the Yemeni conflict, after the United States and the United Kingdom launched joint air strikes on Houthi targets last week.

Central Command said the search effort searched more than 21,000 square miles of ocean and included assistance from the Japanese and Spanish navies.

Houthi militants continued their strikes on civilian cargo shipping and American warships despite numerous American air strikes on their positions. The escalation of Yemen's decade-long civil war threatens the global shipping market and could represent a new regional war in the Middle East.