Iran’s Revolutionary Guards said on Thursday they targeted a US airbase at 0450 local time after what they described as an early morning American attack near Bandar Abbas airport, as tensions flared again around the Strait of Hormuz despite an ongoing ceasefire effort.The IRGC warned that any repeat of what it called aggression would draw a “more decisive” response and said responsibility for the consequences lay with the “aggressor.”Also read: US warns ties with Iran’s Strait of Hormuz authority may bring sanctions for 'anyone' involvedThe exchange came after a US official told Reuters that the US military carried out fresh overnight strikes inside Iran targeting a military site believed to pose a threat to US forces and commercial maritime traffic in the Strait of Hormuz. The official, speaking on condition of anonymity, said US forces also intercepted and shot down multiple Iranian drones that posed a similar threat.Iran’s semi-official Tasnim news agency separately reported that the IRGC navy fired on a US tanker that had allegedly “tried to pass through the Strait of Hormuz by turning off its radar system.”Tasnim said US forces responded by firing “at a scorched area around Bandar Abbas,” adding that “the sound of the explosions was related to this incident” and “did not cause any casualties or property damage.”Strait of Hormuz flashpoint reignitesThe latest confrontation unfolded during negotiations aimed at preserving a fragile ceasefire between Washington and Tehran after a three-month conflict that began on February 28 with US and Israeli attacks on Iran.According to CBS News, a US official described Wednesday’s military action as “defensive” and aimed at maintaining the ceasefire. The report said US forces shot down four Iranian drones and struck a ground control station in Bandar Abbas that was preparing to launch a fifth drone.The drones “posed a threat near the Strait of Hormuz,” CBS News reported, citing the official.“These actions were measured, purely defensive, and intended to maintain the ceasefire,” the official told CBS News.Tasnim separately reported that Iranian naval forces confronted four vessels attempting to cross the Strait of Hormuz and enter the Gulf “without coordinating with Iranian authorities.”Citing an informed military official, the agency said the vessels were initially warned by Iranian naval forces before warning shots were fired after they allegedly ignored instructions, forcing them to turn back.Also read: Three oil, LNG tankers exit Hormuz with transponders offTrump says Hormuz will stay openUS President Donald Trump on Wednesday reiterated that he remained committed to securing a ceasefire arrangement with Iran, while insisting Tehran would not be allowed to obtain nuclear weapons.“Iran cannot have nuclear weapons. I'm doing that for the world, not just for us,” Trump said.Speaking about the Strait of Hormuz, Trump said it would remain “open to everybody” as part of ongoing ceasefire negotiations.Earlier on Wednesday, Trump also dismissed an Iranian state media report claiming Iran and Oman would jointly manage shipping through the Strait of Hormuz as part of a peace arrangement.The United States simultaneously intensified economic pressure on Tehran by imposing sanctions on Iran’s Persian Gulf Strait Authority (PGSA), accusing it of using the body to “extort” commercial vessels transiting through the Strait of Hormuz and funneling revenue to the IRGC.The US military had previously carried out what it described as defensive strikes against Iran on Monday, targeting boats allegedly attempting to lay mines and missile launch sites that US Central Command said threatened American forces and maritime traffic in the region.