The chief engineer of a Chinese-owned oil tanker attacked near the Strait of Hormuz says it is "still unclear" who fired on the vessel.Chinese media Caixin reported on Thursday, local time, it was the first known attack on one of the country's oil tankers since the outbreak of the Iran war.The Marshall Islands‑flagged oil products and chemical tanker, JV Innovation, reported to nearby ships on Monday that a fire had broken out on its deck.Iran war live updates: For the latest news on the Middle East crisis, read our blog.The incident took place off the United Arab Emirates coast, close to Mina Saqr on the Persian Gulf side of the strait.Liu Haining, the vessel's chief engineer, had disembarked a week earlier, as part of a scheduled crew rotation.He told the ABC that his colleagues still on board said the bow of the ship was hit and caught fire but no casualties were reported."At this stage, there's no way to confirm who attacked it," he said."It probably wasn't a missile — more likely artillery shells or possibly a drone They ended up going in circles, caught in a difficult situation with no clear way forward or back."Hundreds of ships and an estimated 20,000 seafarers remain trapped inside the Gulf, with traffic through the strait paralysed after renewed attacks on ships earlier this week."Anyone who operates oil tankers or carries flammable and explosive chemicals knows that sailing fully loaded is like carrying a massive bomb on your back," Mr Liu said."You can't afford even the slightest mistake