Iranian forces have seized a cargo ship, flagged to the Pacific island nation of the Marshall Islands, off the coast of Iran, senior American defense officials told NBC News on Tuesday.
The Iranian Revolutionary Guard fired across the bow of the ship, then boarded it, the officials said.
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The ship, the Maersk Tigris, was in Iranian waters, preparing to enter the Strait of Hormuz, which connects the Persian Gulf to the Arabian Sea, the officials said.
A U.S. Navy destroyer, the Farragut, is headed to the area, and Navy planes are in the air watching, the officials said.
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A spokesperson from Maersk told NBC News' that the Maersk Tigris is currently being run on what they called a "time charter" by Rickmers Ship Management, which lists its head offices as Hamburg, Germany, and Singapore on its website.
Courtney Kube and Alexander Smith contributed reporting.
This developing story originally appeared on NBCNews.com. Please check back for updates.