The Saudi-led military coalition engaged in Yemen said on Monday that the Iran-aligned Houthi movement had seized a vessel towing a South Korean drilling rig at the south end of the Red Sea.
Coalition spokesman Colonel Turki al-Malki said in a statement carried on Saudi state media that the vessel was seized late on Sunday by armed Houthis. He did not say how many crew members were onboard the ship.
A senior Houthi official told Reuters afterward that the group's forces had seized a "suspect vessel" in the Red Sea and that the crew was being treated well.
"Yemeni coast guards…are checking to see whether (the ship) belongs to the countries of aggression or to South Korea, in which case it will be released after completing legal procedures," said Mohammed Ali al-Houthi.
The coalition spokesman said the seizure of the ship was a "terrorist operation" that posed a threat to the freedom of international navigation and world trade.
The Saudi-led alliance intervened in Yemen in March 2015 against the Houthis after the group ousted the internationally recognised government from power in the capital Sanaa.
Houthi forces have been driven away from most of Yemen's coast over the course of the conflict but still hold Hudaydah, the country's biggest Red Sea port and base of the group's navy.
The Houthis have in the past targeted vessels off Yemen, which lies on one side of the Bab al-Mandeb strait at the southern mouth of the Red Sea, one of the world's most heavily travelled oil tanker routes.