Satellite image monitoring shows that traffic in the Strait of Hormuz has come to a complete standstill.
The warnings came after the US terrorist military carried out a fresh act of aggression against Iran, targeting multiple cities in southern Iran.
In response, the Khatam al-Anbiya Headquarters announced the complete closure of the Strait of Hormuz, a vital chokepoint through which roughly one-fifth of global petroleum passes.
In a separate statement, the IRGC Navy warned that any vessel approaching the strategic waterway would face decisive action.
It further warned all oil tankers and commercial vessels currently operating in the Persian Gulf and the Sea of Oman not to leave their anchorages.
Meanwhile, in response to the latest aggression, IRGC aerospace and naval divisions and the Islamic Republic of Iran Army carried out coordinated attacks on 18 American military targets across the region.