American forces shot down a drone off Yemen, and later destroyed an explosives-laden unmanned surface vessel threatening ships in the Red Sea, the US military said. Yemen’s Iran-backed Houthi rebels launched two anti-ship missiles possibly aimed at a cargo ship in the Red Sea, but the missiles did not hit the vessel. Houthi military activity and US strikes and shootdowns have increased, presenting challenges for Washington as it prepares a response to the killing of three American soldiers in a drone attack in Jordan over the weekend. CENTCOM said US forces shot down a drone over the Gulf of Aden early on Thursday, while it blamed the Houthis for the bomb-rigged surface vessel, the destruction of which resulted in “significant secondary explosions.” The Houthis later fired two anti-ship ballistic missiles towards the M/V Koi in the Red Sea, but the missiles impacted in the water without hitting the ship. The United States also destroyed 10 Houthi drones and a ground control station, while an American warship shot down a missile fired by the rebels as well as three Iranian drones. The Houthis have been targeting Red Sea shipping in support of Palestinians in Gaza, and have declared American and British interests to be legitimate targets. Houthi military spokesman Yahya Saree said on social media that the rebels targeted a British commercial ship in the Red Sea “in victory for the oppression of the Palestinian people and as part of a response to the American-British aggression against our country.” The United States set up a multinational naval task force aimed at protecting shipping on the transit route in the Middle East.