Yemen’s Houthis said their naval forces carried out an operation targeting an “American merchant ship” in the Gulf of Aden hours after firing missiles at U.S. Navy destroyer Gravely.

They targeted the “American merchant ship KOI … with several appropriate naval missiles,” Houthi military spokesperson Yahya Sarea said in a statement.

The Liberian-flagged container ship KOI is operated by UK-based Oceonix Services. The company’s fleet includes the oil tanker Marlin Luanda, which was damaged by a missile on Saturday, shipping data showed.

British maritime security firm Ambrey on Wednesday said that a merchant vessel reported an explosion on its starboard after it was targeted with a missile while underway 69 nautical miles southwest of Aden, Yemen.

“Ambrey was aware that a missile was fired from Dimnat Khadir District, Taiz Governorate, Yemen,” it added in an advisory note.

Ambrey, however, did not mention whether this vessel was the Koi.

The Iran-aligned Houthi militants, who control the most populous parts of Yemen, have launched wave after wave of exploding drones and missiles at commercial vessels since Nov. 19, in what they say is a response to Israel’s military operations in Gaza.

The Houthi campaign has disrupted international shipping, causing some companies to suspend transits through the Red Sea and instead take the much longer, costlier journey around Africa.

The U.S. and Britain have launched strikes on Houthi targets in Yemen, and returned the militia to a list of terrorist groups as turmoil from the Israel-Hamas war spreads through the region.