The 5th fleet said that IRGC support ship “Shahid Baziar” was towing a Saildrone Explorer unmanned surface vessel in an attempt to detain it on Monday. It added that the vessel was US government property and equipped with sensors, radars and cameras for navigation and data collection.

The nearby US Navy patrol coastal ship USS Thunderbolt responded, and the fleet also launched an MH-60S Sea Hawk helicopter from a base in nearby Bahrain.

The US Navy said its actions forced the IRGC vessel to disconnect to the towing line to the vessel and leave the area four hours later.

The commander of US Naval Forces Central Command, US 5th Fleet and Combined Maritime Force, Brad Cooper, said: “IRGC’s actions were flagrant, unwarranted and inconsistent with the behaviour of a professional maritime force.”

This incident comes at a sensitive time when tensions remain high in the region as negotiations between the US and Iran to restore its abandoned 2015 nuclear deal are ongoing.

It also comes a week after US forces struck facilities used by groups affiliated with the IRGC in Syria.