Search still on for two missing Navy SEALs who fell into sea off Somalia coast

The guided-missile destroyer USS Mason sails alongside the Japanese destroyer Akebono in the Gulf of Aden in November. U.S. military sources said Monday two Navy SEALs who were lost at sea off Somalia last week were seeking to stop arms shipments to Iran. File Photo by PFC3 Samantha Alaman/U.S. Navy

Jan. 15 (UPI) -- Two U.S. Navy SEALs who remain missing off the coast of Somalia were attempting to board a ship suspected of transporting Iranian weapons through the Gulf of Aden when they fell overboard, reports indicated Monday.

The SEALs went missing on Thursday after it was reported they fell into rough waves at sea while attempting to board an alleged enemy ship during the night.

They were lost at sea while searching for a weapons shipment on board a small boat that was bound for Yemen off the southwestern tip of the Arabian Peninsula, a U.S. defense official told NBC News.

The ship-boarding mission -- which is known to be a dangerous task -- was given the order to proceed after U.S. officials suspected the craft of transporting Iranian weapons through the Gulf of Aden, military sources told the Washington Post.

The SEALs were "forward-deployed" to the area of the U.S. 5th Fleet operations to support a "wide variety of missions," the U.S. Central Command said in a statement issued last week.

National Security Council spokesman John Kirby said Sunday the accident at sea was not related to the recent U.S. and British airstrikes against the Houthis, indicating the Washington is watching the situation "very, very closely."

"This was normal interdiction operations that we've been conducting for some time to try to disrupt that flow of weapons supplies to Yemen," Kirby said on CBS News' Face The Nation.