Iran's Islamic Revolutionary Guard Corps' (IRGC) said Thursday that three oil tankers exploded and caught fire after striking naval mines while attempting to transit what it described as "the unauthorized southern route" through the Strait of Hormuz.

Axar.az reports, ciitng CBS, in a statement, the IRGC Navy's public relations office said the incidents occurred over the past 24 hours, adding that the vessels were subsequently stranded along the southern shores of the strait.

The U.S. has encouraged shippers to use a southern shipping lane through the vital waterway, which President Trump himself declared mine-free at the end of August. Iran insists vessels can only transit the strait through routes it administers closer to its coast in the north of the strait, in coordination with Iranian authorities.

"These oil tankers had switched off all their radar and navigation systems," the IRGC added, referring to a common practice for vessels trying to avoid either U.S. or Iranian-imposed blockades in the strait and surrounding waters.

The vessels, "disregarding warnings from the IRGC Navy, were attempting to exit through the unauthorized southern route of the Strait of Hormuz when they struck naval mines and exploded," the IRGC said.

The IRGC said it held the vessels' owners and crews responsible for using the route that Tehran has warned against for months.