The Houthis have claimed one of their most significant strikes since they started launching missiles at ships in the Red Sea, after two projectiles hit a Belize-flagged cargo ship. The Yemeni rebels claimed the ship was at risk of sinking, a significant propaganda victory for the Houthis if confirmed. The security firm of the Rubymar, which was sailing from the United Arab Emirates to Bulgaria, said the crew had been evacuated safely but did not confirm a sinking. The security company LSS-SAPU said the vessel was struck astern on Sunday, although there was nothing flammable onboard. “We are unsure [of the ship’s condition]. There is nobody onboard now,” the spokesperson said. “The owners and managers are considering options for towage.” The ship was struck 93 miles east of Aden and follows Houthi claims that they had shot down a US drone over the port of Hodeidah. The Houthi military spokesperson, Yahya Saree, said in a televised address on Monday that the Rubymar suffered “catastrophic damages and came to a complete halt” after being targeted in a military operation. He added: “As a result of the extensive damage the ship suffered, it is now at risk of potential sinking in the Gulf of Aden. During the operation, we made sure that the ship’s crew exited safely.” Separately on Monday, the security firm Ambrey said another vessel, a US-owned and Greek-flagged bulk carrier, had called for military assistance citing a “missile attack”. The UK Maritime Organisation also confirmed the incident 100 nautical miles (185km) off Aden in Yemen, with both sources reporting the vessel’s crew were safe. The attacks came three days after the US classified the Houthis as a terrorist organisation and on the day the EU prepared to launch its own naval protection operation in the region. The EU operation, named Aspides, an ancient Greek word for shield, involves three frigates for what will be initially a year-long mission. The EU frigates under Italian command come from Italy, Germany and Belgium. British sources are not expecting the UK’s campaign against Houthi missile launchers to have a short-term impact, but say it is gradually degrading the Houthis’ ability to act. The European operation does not provide for attacks on Houthi positions in Yemen but instead purely defensive operations. The Houthis say they are undertaking the attacks as solidarity with the people of Gaza, and the targets are confined to Israeli-owned ships, or ships connected with the US and UK. An attempt by David Cameron, the UK foreign secretary, to enlist the active support of China when he met the Chinese foreign minister in Munich failed to bear fruit. China, the UK argues, is one of the key users of the Red Sea shipping lanes, and it is hoping Beijing will put pressure on Tehran to tell the Houthis to stop. There are signs that Iran has told some of its proxy groups in Iraq to hold back, but the relationship between the Houthis and Iranians is more fluid. The US secretary of state, Antony Blinken, and India’s external affairs minister, S Jaishankar, also discussed the need to ensure freedom of navigation in the Red Sea, in a meeting on the sidelines of the Munich security conference on Friday. Indian exporters have been complaining about a large rise in shipment costs to Europe, the US east coast, north Africa and parts of the Middle East as shipping companies are not only charging more for the longer route but also imposing many insurance premiums. While this has not yet been reflected in the export numbers as older orders are being honoured, if the conflict continues, things may deteriorate. Total weekly toll revenues from the Suez canal have dropped by 40% since the end of November to $28m (£22m), according to the maritime freight management firm Veson Nautical. Since November, the Houthis have repeatedly targeted ships in the Red Sea and surrounding waters in response to Israel’s war in the Gaza Strip. They have frequently targeted vessels with tenuous or no clear links to Israel, imperilling shipping in a key route for trade among Asia, the Middle East and Europe. The attacks have prompted several companies to halt Red Sea voyages and take a longer and more expensive route around Africa. American and British warplanes have carried out retaliatory strikes across Yemen.