Iran's Revolutionary Guards' media say IRGC Navy has intercepted and seized ships smuggling more than 4.5 million liters of fuel.
The operation resulted in the detention of 34 foreign crew members.
The vessels are said to be small local ships rather than conventional international tankers.
The nationalities of the foreign sailors and the countries to which the vessels belong were not disclosed.
The total of smuggled fuel seized is under 30,000 barrels and a relatively small amount by oil trading standards.
Iran has some of the lowest fuel prices in the world due to extensive subsidies and the devaluation of the rial. The regime is combating widespread fuel smuggling, both through land routes to neighboring countries and maritime channels to Gulf Arab states.
Commander Ali Ozmaee of the Fifth Naval Region of the Revolutionary Guard provided details of the seizure, saying that one vessel, carrying 2,280,000 liters of fuel and crewed by 13 foreigners, was apprehended south of Abu Musa Island. A second ship, with 21 foreign crew members and transporting 2,300,000 liters of fuel, was also seized by Revolutionary Guard forces.
The incident follows a pattern of the Revolutionary Guard's involvement in intercepting foreign ships in the Persian Gulf. The United States had previously reported that Iran engaged in aggressive actions against over 20 ships in the region within the past two years.
In a separate incident on July 7 of this year, the Revolutionary Guard claimed the seizure of a vessel with 12 foreign crew members carrying 900 tons of smuggled fuel.