A U.S. military helicopter fired on a merchant vessel trying to traverse the United States’s Strait of Hormuz blockade, the first such instance in weeks.

The U.S. fired at the ship’s rudder to disable it after the crew ignored multiple warnings to stop, a U.S. official told the Wall Street Journal. The ship appeared to be transferring its crew to another ship after the attack.

The predawn attack was flagged by the maritime security firm Vanguard, which identified the ship as the Vela Nova, and said it was hit by a missile about 71 nautical miles from the coast of Pakistan.

“The missile struck the vessel, causing a fire that was subsequently extinguished,” an initial report on the incident from the firm read, according to the Wall Street Journal.

All 17 crew members were accounted for, with no reports of casualties.

The Washington Examiner reached out to U.S. Central Command for confirmation and comment.

Attacks against ships trying to escape the blockade were common during the first blockade, which began in April, but have been less common after it was reinstated following the collapse of the memorandum of understanding last month. The last attack on a ship attempting to break the blockade was in July.

The attacks typically involve the precise targeting of the engine room or rudder, disabling the vessel without significant casualties.

IRAN SHIPPED $6 BILLION WORTH OF OIL PRODUCTS BEFORE US BLOCKADE WAS REINSTATED

The naval blockade of Iran has been one of the most effective ways of inflicting crippling economic damage on Iran, as nearly all its oil exports are done by sea. U.S. intelligence originally estimated that Iran could hold out until August when the initial blockade was put into place, but its lifting in June effectively reset the timer.

In the 26 days between the signing of the MOU and the reinstatement of the U.S. blockade, Tehran shipped over 80 million barrels of oil, roughly $6 billion worth, to foreign buyers.