IRGC Navy Declares Strait of Hormuz Closed to All Vessels

Iran’s Islamic Revolutionary Guard Corps Navy said on Saturday that the Strait of Hormuz has been “closed to all vessels” and warned ships against approaching the strategic waterway, Middle East Monitor reported, citing Iran’s Fars news agency. Middle East Eye framed the move as a re-closure following the day’s Israeli strikes on southern Lebanon.

What we know

The IRGC Navy’s statement, relayed by Fars, declared the strait closed and explicitly warned vessels against approaching, per Middle East Monitor. Tehran tied the announcement to what it called Israeli and US violations of the recent US-Iran agreement. Middle East Eye’s report attached the closure directly to Saturday’s Israeli air campaign across southern Lebanon, where Lebanon’s National News Agency has reported at least 28 killed and where the IDF said it struck after Hezbollah fired more than 50 projectiles.

The IRGC framed the closure as a response to “violations” rather than as a unilateral break with the deal, and Middle East Eye reported Tehran is warning of “further steps being taken.” The closure declaration arrives one day after CENTCOM confirmed the US Navy had lifted its own Hormuz blockade under the post-deal framework.

What we don’t know

The IRGC’s statement is a verbal closure declaration; the operational picture — whether vessels are physically being turned away, whether IRGC fast-attack craft have moved into the strait, and whether mine-laying or escort patterns have changed — has not been confirmed by CENTCOM, the Joint War Committee, or any independent shipping body. No “Notice to Mariners” has been issued at the time of publication. Insurers’ war-risk listings, which moved with the post-deal reopening, have not publicly updated. This is a developing situation.

Context

The closure declaration directly reverses the choreography that produced the first post-deal LNG tanker transit and the Friday window the deal was built around. It also lands inside the same 24-hour cycle as Saturday’s Lebanon strikes — a sequencing that, if Tehran sustains it, links Israel’s southern Lebanon operations to the strait’s transit risk for the first time under the new framework.

For markets, the IRGC statement alone — independent of enforcement — is a fact insurers and tanker owners cannot ignore. The post-deal premium compression in war-risk rates assumed the strait stayed declared-open. A verbal closure by the IRGC Navy resets that assumption regardless of what happens next.

What to watch

1. Whether CENTCOM, the UKMTO, or the Joint War Committee issue any operational confirmation, denial, or guidance to commercial shipping in the next 12 hours.
2. Whether any inbound or outbound vessel currently transiting the strait reports being challenged, escorted, or turned back by IRGC craft.
3. Whether Tehran’s “further steps” language is followed by a concrete physical action — escort denial, mining advisory, or a formal Notice to Mariners — or remains rhetorical through Monday’s open.