The Iranian Revolutionary Guards seized on Monday a ship in the Gulf suspected of carrying smuggled fuel, state media reported.
The official IRNA news agency said the seized ship was carrying more than 1.3 million liters of fuel near Abu Musa Island at the mouth of the strategic Strait of Hormuz.
All 16 crew members, who are Malaysian nationals, were also detained, the report added. It did not say what country's flag the ship sailed under.
IRNA said the ship was carrying nearly 1,312,000 liters of fuel.
The Guards have seized several ships in the area in the past year.
In July, Iran also seized a British-flagged oil tanker, amid high regional tensions over Tehran's collapsing nuclear deal with world powers.