Iran’s Islamic Revolutionary Guard Corps announced late Saturday that it had closed the Strait of Hormuz after firing at and hitting a commercial ship in the critical waterway.

The IRGC claimed one vessel was struck after its forces fired a warning shot and ordered it to change course, Iran International reported.

It vowed any response by the US or allies would draw “severe” retaliation.

It comes after the Trump administration issued its own threat Friday, vowing that if Iran failed to keep the strait open and call off attacks that “it’s not going to be a great day for them.”

A senior US official told Axios’ Barack Ravid that Iranian forces fired on a single merchant ship in the strait and that it was hit.

The drama on the seas came as Iranian and Omani representatives met in Muscat to discuss the crucial chokehold, an international body of water that the US is demanding remain open to commercial shipping.

About 20% of the world’s oil passes through the Strait of Hormuz.

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The US launched strikes on Iranian targets over two days last week in response to attacks on ships making their way through the strait.

The Post has reached out to US Central Command for comment.