The escalation has seen ships mysteriously attacked, drones downed and oil tankers seized Online Cigarettes Store USA in the Strait of Hormuz -- a chokepoint for a third of world's seaborne oil.
Iran's Islamic Revolutionary Guard Corps detained a "foreign tanker" in Gulf waters on July 14 for allegedly smuggling contraband fuel.
"With a capacity of two million litres and 12 foreign crew on board, the vessel was en route to deliver contraband Cheap Newport Cigarettes Online Sale fuel received from Iranian boats to foreign ships," the Guards said at the time.
Maritime tracking service TankerTrackers reported the Panamanian-flagged MT Riah, used in the strait for fuelling other vessels, had crossed into Iranian waters, and at that point its automatic identification system stopped sending signals.
In the most high-profile seizure, the Guards impounded the British-flagged Stena Impero tanker in the Strait Cheap Newport 100s cigarettes of Hormuz on July 19 for breaking "international maritime rules". Iran also seized another ship on July 31 with seven foreign crew onboard over fuel smuggling, but it has not revealed the vessel's identity or the nationality of its crew.