A U.S. official claimed Iran attacked the ship, likely with a missile.
President Donald Trump announced "major combat operations" against Iran on Feb. 28, with massive joint U.S.-Israeli strikes targeting military, government and infrastructure sites.
Despite a memorandum of understanding signed by both countries in June aimed at ending the war, talks broke down and the U.S. and Iran renewed strikes, with the strategic Strait of Hormuz as the primary flashpoint.
Across the region, fighting in Yemen between the Iranian-backed Houthis and Saudi-backed Yemeni forces has intensified in recent weeks and the militia group has also launched strikes on Saudi Arabia.
The United Kingdom Maritime Trade Operations said it has recorded 20 reported attacks in the Strait of Hormuz since Oct. 1, with two incidents reported on Wednesday.
In each case, vessels were struck by what the UKMTO described as "unknown projectiles."
-ABC News' Jamie Dorrington
A U.S. official said Iran lied about a cargo ship that sunk on Wednesday and that Iran attacked the ship, likely with a missile.
Iran claimed the cargo ship sunk after striking a naval mine as it was attempting to navigate the Strait of Hormuz.
-ABC News' Steve Beynon
Iran's Islamic Revolutionary Guard Corps Navy said a cargo ship sunk on Wednesday after striking a naval mine as it was attempting to navigate the Strait of Hormuz via "an unauthorized and hazardous route."
The vessel was carrying more than 2,500 containers and sank in waters south of the strait Wednesday morning due to the intensity of the fire, according to the IRGC.
The U.K. Maritime Trade Operations Center issued new warnings Wednesday after it received reports of two ships being struck by projectiles in separate incidents on Tuesday in the Strait of Hormuz.
The UKMTO posted two "time-late" reports described as "verified" of container ships struck by unknown projectiles on Tuesday.
A 19-ton container ship and a 50-ton container ship both sustained minor damage after each was struck by an unknown projectile, the UKMTO said. No injuries were reported, and the ships were able to continue their passage through the strait.
On Wednesday, the Iranian Revolutionary Guard Corp Navy claimed a container ship moving toward an unauthorized route through the strait "exploded after hitting a naval mine," according to Iranian state-run media.
The IRGC said the container ship sank on Wednesday morning.
-ABC News' Othon Leyva
