STRAIT OF HORMUZ — U.S. forces have identified at least 10 underwater mines in the Strait of Hormuz and have begun directing commercial vessels toward an alternate route farther from Iran that the Navy has spent weeks clearing. The U.S. warned that transiting the normal shipping lane could be "extremely hazardous" because of mines laid in the strait by Iran.

American intelligence assessments in March showed at least a dozen underwater mines in the strait, while a separate U.S. official placed the count at fewer than a dozen. A Pentagon graphic displayed this month indicated that Iran laid new mines in the waterway on April 23.

Iran is currently using two Iranian-manufactured devices in the strait, the Maham 3 and the Maham 7. The Maham 3 is a moored naval mine that uses magnetic and acoustic sensors to detect nearby vessels without physical contact and can engage targets within about 10 feet by analyzing movement to determine when to activate.

The Maham 7, known as a sticking mine, is designed to rest along the seabed and relies on acoustic and three-axis magnetic sensors to detect vessels overhead. It targets medium-sized ships, landing craft and smaller submarines.

Before the current conflict, about 20% of global oil—roughly 15 million barrels of crude per day—flowed through the Strait of Hormuz along with liquefied natural gas shipments. The waterway continues to be a point of contention between Washington and Tehran.

Iran is working with Oman to create a joint mechanism to control traffic through the shipping lanes of the strait, according to Iran. A gallon of gasoline around the country costs an average of $4.50, more than $1.50 higher than before the war started, according to AAA.