US forces have said they destroyed an underwater drone and nearly 20 ballistic missiles in a series of strikes against Yemen’s Houthi rebels, who threatened on Tuesday to step up their attacks in the Red Sea during Ramazan, AFP reports.

The US Central Command (Centcom) said in a statement on Monday night that the strikes were carried out after the Houthis fired two missiles towards a Singaporean-owned, Liberian-flagged merchant ship called the Pinocchio.

“The missiles did not impact the vessel and there were no injuries or damage reported,” Centcom said. Hours later, it added, US forces “conducted six self-defense strikes destroying an unmanned underwater vessel and 18 anti-ship missiles in Houthi controlled areas of Yemen”.

The Houthis claimed responsibility for the attack on the Pinocchio in a statement early on Tuesday, maintaining the missile strike “was accurate”.

The British maritime security agency UKMTO had previously said a ship in the area “reported a sound of an explosion” in its vicinity southwest of the Yemeni port of Salif, and that US-led coalition forces were investigating.