According to the Revolutionary Guard, Iranian forces have "taken administrative control of the strait," it said in a statement.
The statement says that, as part of this, they attacked a ship carrying liquefied fossil gas that "was attempting to travel via an illegal shipping lane south of the Strait of Hormuz."
Trade through the Strait of Hormuz has been severely restricted since the US and Israel attacked Iran in February this year, followed by repeated Iranian attacks on ships.
Iran is blocking the strait, while the US Navy is blocking Iranian naval traffic in the area.
