The Arab Coalition said it intercepted and destroyed an explosives-laden boat launched from Yemen by the Iran-backed Houthi group on Thursday, in an incident that could further increase regional tension.
"The Coalition's naval forces detected an attempt by the terrorist Houthi militia backed by Iran to carry out an imminent act of aggression and terrorism south of the Red Sea using an unmanned, rigged boat launched from Hodeidah province," Coalition spokesman Col Turki Al Malki said.
He did not specify the intended target.
There was no immediate confirmation by the Houthi movement, which had claimed responsibility for the September 14 attacks on two Saudi Aramco oil facilities last weekend. The US said those strikes did not come from Yemen.
The Houthis, who have threatened to widen attacks on Saudi Arabia, 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 vital oil tanker routes.
In July 2018, the group attacked two Saudi tankers in the Red Sea, one of which sustained minimal damage. Riyadh responded by temporarily suspending oil shipments through the strait, which the Houthis have in the past threatened to block.
Col Al Malki said Thursday's foiled attack represented a threat to regional and international security and the safety of maritime routes and international trade.
The incident comes as the US and Saudi Arabia consider responses to Saturday's assault on Saudi oil facilities, which Washington says was sponsored by Iran.
The western-backed coalition intervened in Yemen in March 2015 against the Houthis after they ousted the internationally recognised government in Sanaa in late 2014.
The escalating tension could hamper UN efforts to implement a troop withdrawal deal in the main port of Hodeidah, a lifeline for millions of Yemenis, which was agreed on at peace talks in Sweden last year.
The Yemen conflict has killed tens of thousands and pushed millions to the brink of famine.