Iran Hormuz Re-Closed: Gunboats Fire on Tanker as Military Control Reimposed April 2026

# Iran Hormuz Re-Closed: Gunboats Fire on Tanker as Military Control Reimposed April 2026

> **Quick answer:** Iran declared the Strait of Hormuz "completely open" on April 17 — markets surged, oil crashed 12%. Less than 24 hours later, on April 18, Iran reversed course, reimposing strict military control and accusing the US of "piracy" for keeping its naval blockade active. Iranian Revolutionary Guard gunboats then opened fire on a commercial tanker transiting the waterway. Oil markets reopen Sunday. With the ceasefire expiring April 22 and talks described as simultaneously "very close" and on the brink of collapse, Monday's open will be one of the most volatile oil price events of 2026.

Iran Hormuz re-closed news sent shockwaves through global shipping and energy markets on Saturday, April 18, 2026 — less than 24 hours after a market-moving "completely open" declaration triggered the second-largest oil price crash since the war began. Here is everything you need to know before markets reopen.

## What Happened: The 24-Hour Reversal

On April 17, Iranian Foreign Minister Seyed Abbas Araghchi declared the Strait of Hormuz "completely open" for commercial vessels during the Israel-Lebanon ceasefire period. The announcement was immediate and dramatic: US crude (WTI) plunged 11.4% to $83.85 per barrel, Brent crude fell 9% to $90.38, and the S&P 500 leapt 1.2%, extending its record gains. Markets had priced in a genuine diplomatic thaw.

By Saturday morning, April 18, that thaw had frozen over.