BREAKING: Iran closes Strait of Hormuz to international shipping

Iran's Islamic Revolutionary Guard Corps announced the closure of the Strait of Hormuz to international navigation until further notice on February 28, in a move with potentially severe consequences for global energy markets, Iranian ANHA reported.

The IRGC said the closure was a direct response to US and Israeli strikes on Iranian territory. A senior Revolutionary Guard official confirmed the decision had already taken effect, ANHA reported on February 28.

Vessels in the area were receiving repeated radio warnings on high-frequency channels from the Iranian side, stating that no tanker would be permitted to transit the strait.

Newsbase monitoring of the strait on February 28 witnessed several dozen vessels currently going through the narrow waterway, Marine Traffic showed. 

The Strait of Hormuz is the world's most critical oil chokepoint, with around 20% of global oil supplies passing through it daily. Earlier data cited during the conflict showed approximately 13mn barrels per day of crude oil transited the strait in 2025, accounting for roughly 31% of global seaborne crude flows.

The closure, if sustained, would cut off exports from Saudi Arabia, the UAE, Kuwait, Iraq and Qatar, which together account for a substantial share of global oil production.

Saudi Arabia is reported to have been increasing production as a contingency ahead of potential conflict, though land and pipeline alternatives to the strait have limited capacity to absorb the volume of seaborne exports affected.

Oil markets had already been moving higher on the day as fighting spread across the Middle East. Brent crude had risen to $71.41 per barrel in earlier trading, though markets are now closed and the full impact of the closure will likely be reflected when trading resumes.

The closure came as Iran's IRGC confirmed it had struck the US Fifth Fleet headquarters in Bahrain, American bases in Qatar and the UAE and targets inside Israel as part of Operation True Promise 4.

Iran's internet connectivity stood at 4% of normal levels, its airspace remained closed and the rial had fallen to a record low of IRR1,749,500 against the dollar.

This story is developing. Details remain unverified and subject to change.