Only days after the United States announced that it had cleared naval mines from international shipping lanes in the Strait of Hormuz, Iran appeared to be prepared with an unconventional way to mine the waterway again.
A report by France 24 highlighted claims that Iran had modified Fajr-5 rocket launchers so they could fire naval mines into the Strait of Hormuz, a development that could introduce a new threat to shipping through the strategic waterway.
According to US Central Command, American forces struck two Iranian rocket launchers on Sunday after detecting members of the Islamic Revolutionary Guard Corps preparing to fire rockets carrying naval mines into the strait.
The strikes drew attention to a capability that has not been widely known and which could allow Iran to threaten maritime traffic without sending mine-laying boats into waters patrolled by US forces.
A Naval Mine Fired From Land
The New York Times reported that an artillery rocket capable of delivering a mine into the water is highly unusual and could give Tehran another means of disrupting the Strait of Hormuz. The newspaper noted that Iran had previously demonstrated such a capability.
In June 2024, Maritime Executive reported that Iran had displayed a modified version of its Fajr-5 rocket during naval exercises, capable of carrying and releasing a single floating mine into the water.
During the naval drill conducted by the Revolutionary Guard’s naval force, images broadcast on television showed the system being successfully used to deploy naval mines in Gulf waters.
Under this modified configuration, the rocket’s conventional warhead is replaced by a naval mine. After launch, the mine separates from the rocket body at a predetermined distance from the target area and settles on the surface of the water using a proximity fuse and a section of the rocket structure that serves as a flotation device.
This mechanism could allow the system to deploy dozens of mines across a wide area and at strategic depth during successive launches. Naval mines are normally laid by ships, submarines, aircraft or small boats, exposing both the vessels and their crews to detection and attack.
What Is Known About the Modified Fajr-5?
The Fajr-5 emerged as part of Iran’s Fajr rocket system during the 1980s. The Fajr family was later used by several Iranian allies across the region, while different models and variants were developed over time.
The rocket is designed to be fired from a multiple-launch rocket system, allowing concentrated barrages to be delivered within a short period and saturating the targeted area with a large number of projectiles.
It was developed primarily to strike fixed targets or large-area objectives such as military facilities, airports, command centres, troop concentrations and industrial zones, rather than conducting precision strikes against small or moving targets.
The Fajr-5 is also large compared with conventional artillery rockets, allowing it to carry a comparatively heavy warhead and generate a broad destructive effect across the target area.
Technical Specifications
The Fajr-5 has a calibre of approximately 333 millimetres and is around 6.48 metres long. Its total weight is estimated at about 915 kilograms, while its warhead weighs roughly 175 kilograms and contains around 90 kilograms of high explosives.
The basic version has an estimated range of 75 kilometres, although available specifications differ depending on the variant.
The rocket is produced in both single-stage and two-stage versions. The single-stage version has an effective range of 75 kilometres, while the two-stage version can reach approximately 190 kilometres.
In the thermobaric model, explosive power is estimated at around one and a half times that of TNT, significantly increasing both the destructive radius and thermal effect.
The Fajr-5 has no guidance system and instead relies on pre-set coordinates, launch angle and ballistic range. Its accuracy is therefore lower than that of modern guided missiles.
It uses a solid-fuel rocket motor, allowing rapid response, easier storage and launch readiness within minutes.
The system is fired from multiple-launch platforms, enabling concentrated barrages across a wide area in a short period.
Why the Fajr-5 Changes the Equation
Although modern double-hulled oil tankers can withstand relatively small punctures, floating mines can create uncertainty over which routes are safe for navigation. Even a limited number of mines could force extensive search and clearance operations.
The Fajr-5 is a 333-millimetre artillery rocket launched from a mobile platform. A mine-carrying version could allow Iranian forces to deploy a mine into the strait directly from the shoreline and then relocate the launcher.
The New York Times estimated that such a mine could contain dozens of pounds of explosives, considerably less than larger naval mines that carry hundreds of pounds. The size of the rocket also limits the type of mine it can deliver.
A small mine could still damage a warship, while fishing boats and other smaller vessels would face a more serious threat.
More importantly, rocket-delivered mines could drift.
Unlike larger mines anchored in place or resting on the seabed, winds and currents could move these weapons after they enter the water. They could drift into shipping lanes, reach the open ocean or eventually wash ashore, creating wider disruption.
Why Now?
On 25 August, President Donald Trump said that international waters in the Strait of Hormuz had been cleared of mines and warned that Iranian vessels attempting to lay new mines would be destroyed.
That gave Iran a clear incentive to find another method of introducing mines into the water without relying on mine-laying vessels.
Such a capability would not necessarily allow Tehran to close the strait entirely. But completely shutting down the Strait of Hormuz may not be necessary to create a major economic impact.
Commercial vessels generally require confidence that their routes are safe. Even the possibility that floating mines are present could force shipping companies to conduct searches and clearance operations, slowing maritime traffic and adding another layer of uncertainty.
That means the potential impact of the weapon could be far greater than the size of its explosive charge.
If the US account is accurate, rocket-launched mines may not give Tehran a new way to close the Strait of Hormuz outright. They could, however, give Iran another way to keep the world questioning whether the strait is genuinely open.
