Iran's <a href="https://www.thenationalnews.com/tags/irgc/" target="_blank">Islamic Revolutionary Guard Corps</a> seized a commercial tanker in the Arabian Gulf on Thursday, the US Navy has said. The Bahrain-based <a href="https://www.thenationalnews.com/mena/2023/05/23/us-led-maritime-training-task-force-established-in-middle-east/" target="_blank">US Navy Fifth Fleet</a> said the IRGC “forcibly seized a commercial vessel possibly engaged in smuggling activity”. Iran's Fars news agency said the vessel, which was holding 900 metric tonnes of “smuggled fuel” and 12 crew members, was seized in line with a court order. It comes a day after the US had accused Iranian forces of <a href="https://www.thenationalnews.com/mena/2023/07/06/iran-claims-it-had-court-order-to-seize-us-oil-tanker-in-gulf-of-oman/" target="_blank">two similar attempts off Oman</a>. The US Navy said its forces monitored the incident in international waters but “assessed the circumstances of this event did not warrant further response”. The commercial ship was not identified. “US forces remain vigilant and ready to protect navigational rights of lawful maritime traffic in the Middle East's critical waters,” the US Navy said. Iran has some of the world's cheapest fuel due to heavy subsidies and the plunge in the value of its currency. It has been fighting rampant fuel smuggling over land to neighbouring countries and by sea. British maritime security company Ambrey said on Thursday it was aware of an attempted seizure by Iranian forces of a small Tanzanian flagged tanker, around 59 nautical miles north-east of the Saudi port city of Dammam. On Wednesday, Iran claimed it had a court order to seize a US-managed <a href="https://www.thenationalnews.com/mena/2023/07/06/iran-oil-tanker-strait-of-hormuz/">vessel </a>that its navy shot at off Oman. An Iranian coastguard agency told state-run media on Thursday that the incident in the Strait of Hormuz was triggered by a collision between an oil tanker and an Iranian vessel. The US Navy said it had blocked two attempts by the Iranian navy to seize commercial tankers in international waters off Oman, including one case in which the Iranians fired shots. In both cases, the US Central Command said the Iranians departed after a US destroyer appeared on the scene. The maritime services in Iran said one of the two tankers, the Bahamian-flagged Richmond Voyager, had collided with an Iranian vessel, seriously injuring five crew members, according to state news agency IRNA. They said the collision had occurred on Tuesday, leading to the flooding of the Iranian vessel. “The Richmond Voyager continued on its way, regardless of international maritime rules and regulations,” IRNA said. The report said the tanker changed course before entering Oman's territorial waters.