CBS News, citing U.S. officials speaking on the condition of anonymity, reported that U.S. military forces have identified at least 10 naval mines in the Strait of Hormuz in their latest intelligence assessment, an action that Washington says has placed the passage of vessels through the normal routes of this strategic waterway at serious risk.

According to the report, U.S. officials believe the Islamic Republic has deployed Iranian-made “Maham-3” and “Maham-7” limpet mines in the Strait of Hormuz. CBS News had previously reported that U.S. intelligence assessments indicated the presence of at least 12 underwater mines in the area, although a U.S. official at the time stated that the figure was lower.

The United States has warned that the passage of vessels through regular shipping lanes in the Strait of Hormuz could be “extremely dangerous,” a warning issued amid rising tensions between Tehran and Washington.

The Pentagon had also previously released a graphic illustration stating that the Islamic Republic laid new mines in the Strait of Hormuz on April 23, a move that has heightened concerns over the security of one of the world’s most critical energy transit routes.