How Many Naval Mines Does Iran Have? From 8,000 to a Few Hundred

Somewhere between 5,000 and 8,000, depending on who was counting and when.

The Defense Intelligence Agency estimated in 2019 that Iran held more than 5,000 naval mines and could lay them quickly from small, fast boats. Estimates given to Congress before the war put the stock at 5,000 to 6,000. In his written statement to the Senate Armed Services Committee on May 14, 2026, Adm. Brad Cooper, the commander of Central Command, put the prewar inventory at about 8,000. Iran has never published a figure.

The spread between 5,000 and 8,000 shows how hard mines are to count. They are small, cheap, easy to store in ordinary warehouses and easy to build at home, and Iran has made its own designs for decades alongside older Soviet-pattern and Chinese types.

On the US figures, a few hundred, but no independent count exists.

Adm. Cooper told the Senate on May 14 that US forces had destroyed more than 90 percent of Iran’s mine inventory in more than 700 strikes on mine-related targets. He did not say how many were destroyed in depots, how many on boats and how many after they had been laid. Even on his figure, Iran could still hold up to about 800 mines, and a handful in a shipping lane is enough to stop tankers, because insurers and shipowners do not wait for proof before they turn back.

Iran has not said how many it has left. Its navy said on October 29 and 30 that the southern route near Oman’s coast was “contaminated” with mines, which is a claim about where mines are, not how many Iran holds. How far the rest of Iran’s arsenal has been run down is covered in our explainer on how many missiles Iran has left.

Iran has three main kinds: moored mines that float on a cable, bottom mines that lie on the seabed, and a reported rocket-propelled mine that rises from deep water.

The Maham-1 is a moored contact mine of the old kind, with horns that set it off when a hull touches them. The Maham-3 is also moored, but it is an influence mine: it listens for the sound of a passing ship, and some versions add a magnetic sensor, so it can be set to explode without being touched. It can be moored in water up to about 100 meters deep, deeper than most of the strait’s shipping channel.

The Maham-2 and Maham-7 are bottom mines. They sit on the seabed in shallower water and fire when they sense a ship’s sound or magnetic field overhead. The Maham-7 is shaped to be hard to find with sonar, and it can be dropped from a small boat or a helicopter.

Iran is also reported to have bought the Chinese EM-52, a rocket mine that waits on the seabed and fires a warhead upward at a ship passing above. Its presence in Iran’s stock has been reported for years but never shown publicly. Older Soviet-design M-08 contact mines, which date back to before the First World War, are what Iran used in the 1980s.

A contact mine needs a ship to hit it; an influence mine only needs a ship to pass close by.

Contact mines are simple and cheap, and they drift or sit on a cable just below the surface. Influence mines are the bigger problem for navies. Their sensors pick up a ship’s engine noise, the change in the magnetic field caused by a steel hull, or the drop in water pressure as a large ship moves over them, and some can be set to let the first few ships pass before they fire. That is why minehunters are built with wooden or fiberglass hulls, and why clearing a field takes months rather than days. Our explainer on how many minesweepers the US Navy has shows how thin the force that does that work has become.

A limpet mine is something else: a charge fixed to a ship’s hull by hand, usually by divers or from a small boat. The tanker set on fire off Khasab, Oman, on October 29 was hit with two of them, as we reported in the Khasab limpet mine attack.

Mostly from small boats, which is why the United States has hunted them from the first days of the war.

US officials said in mid-March 2026 that Iran had begun laying mines in the strait from small boats rather than warships, a few dozen at first. Central Command said US forces had destroyed 16 Iranian minelayers near the Strait of Hormuz on March 10. Iran has also shown helicopters dropping mines in exercises, and in the 1980s it used converted landing ships such as the Iran Ajr.

The US mine-clearance mission in the strait began on April 11. President Donald Trump said on August 25 that all mines had been removed or detonated in the strait’s international waters, and Adm. Cooper said on October 25 that the primary shipping routes were free and clear of Iranian sea mines.

Yes. Iran mined the Gulf during the Tanker War of the 1980s, and the United States went to battle over it.

The reflagged Kuwaiti tanker Bridgeton hit a mine on July 24, 1987, on the first US-escorted convoy of the war. On September 21, 1987, US Army helicopters caught the Iranian ship Iran Ajr laying mines at night near Bahrain; Navy SEALs boarded it and found M-08 contact mines on its deck. On April 14, 1988, the frigate USS Samuel B. Roberts struck an M-08 mine in the central Gulf and nearly sank. Navy specialists matched nearby mines to the series found on the Iran Ajr, and four days later the United States struck Iranian oil platforms and warships in Operation Praying Mantis.