US forces destroyed a Houthi underwater drone on Saturday, making this the first known instance of the Yemeni rebel group employing such a device.

The news will add to the concerns of international shipping operators, that have cut transits through the Red Sea by half since the Houthis began attacking commercial vessels off Yemen’s waters.

“This is the first observed Houthi employment of a UUV [unmanned underwater vessel] since [Houthi] attacks began on 23 October,” the US Central Command (Centcom) said in a situation report on its activities for 17 February.