Editor’s Note: Leonardo Jacopo Maria Mazzucco is a specialist on maritime operations in the Persian Gulf and nearby waters. He has previously written for Stimson about the Saudi navy and about arms and drug trafficking.
By Barbara Slavin, Distinguished Fellow, Middle East Perspectives
In 1984, a sea mines act of sabotage, whose attribution remains debated, disrupted navigation across the Red Sea’s gateways — the Suez Canal and the Bab el-Mandeb Strait. In response to regional requests, a U.S.-led coalition conducted countermeasure operations, restoring safe shipping in the strategic waterway connecting the Mediterranean Sea and the Indian Ocean.
Forty years later, naval mines still represent a potential threat to seaborne trade, energy products, and underwater digital infrastructures in and around the Red Sea. The Yemeni insurgent group Ansar Allah, commonly known as the Houthis, has held free navigation in the region hostage since mid-November 2023, launching hundreds of missile, drone, and boat swarm attacks on commercial shipping in support of Palestinians fighting Israelis in Gaza. If the war continues, the Houthis might also resort to laying mines to try to close the Bab el-Mandeb or to attack international shipping in the Red Sea.
Throughout history, actors with limited naval capabilities confronting more powerful adversaries have used sea mines to level the playing field. Both Iran and Iraq used mines during their 1980-88 war. After Iraq invaded Kuwait in 1990, it laid over 1,000 mines off Kuwait to prevent a U.S.-led coalition from launching an amphibious landing operation.
Naval mines provide a strategic advantage in the defense doctrine of small states and non-state actors. They are highly regarded as relatively affordable and can be fielded without the support of advanced naval platforms. They impose disproportionate costs on an adversary determined or compelled to clear mine-infested waters, thereby shifting the power dynamics.
Moored mines, anchored on the seabed through cables and floating beneath the surface, play an anti-access function to protect ports and harbors. Drifting mines perform an area denial role as they can travel significant distances from their initial sowing carried by ocean currents.
For much of its history, the Houthi movement focused on projecting force on land. From Sa’dah, a mountainous territory bordering Saudi Arabia, the Houthis used guerrilla warfare in localized clashes with then-Yemeni President Ali Abdullah Saleh’s forces in the 2000s in what became known as the Sa’dah wars.
After the Houthis took over Yemen’s capital of Sana’a in September 2014, their military campaign shifted west and south to the littoral areas overlooking the Red Sea and the Bab-El-Mandeb. The Houthi capture of the port of Hodeida in November 2021 marked a significant turning point, extending the group’s control over large swaths of Yemen’s western coast and accessing the Yemeni Army’s stockpiles of weapons and naval assets. This enabled the Houthis to begin to weaponize the maritime domain.
The Houthis are no match for the U.S. and most Persian Gulf Arab countries on a ship-for-ship basis. Yet they have increasingly become a threat to seafarers in and around the Red Sea.
Since early 2017, the Houthis have sown hundreds of mines near Yemen’s Red Sea coasts to prevent Saudi-led forces from launching amphibious operations and seizing outposts crucial to Houthi defenses.
The Houthis have planted mines in shallow waters off major coastal cities, such as Mokha, Al Hodeida, and Midi, and around strategic islands, including Kamaran, the Hanish archipelago, and Buklan. Lacking purpose-built minelayers, the Houthis have used speed boats and fishing vessels to sow the mines.
Some were Soviet-era devices, suggesting that they originated from the Yemen Army’s ammunition stores. However, most are believed to be indigenously manufactured by the Houthis. A close resemblance between the more advanced mines and Iranian-made designs suggests technology transfers from Tehran.
The most basic devices include floating mines made from household gas cylinders filled with explosives and fitted with contact detonators. More sophisticated models are fixed on the seabed through an anchoring mechanism and equipped with contact or influence (magnetic or acoustic) detonators. The Houthi inventory also reportedly includes limpet mines, which attach to a ship’s hull with magnets.
The Yemeni insurgent group has made no secret of its expanding arsenal, with new systems trumpeted by Houthi-affiliated media and displayed at a Sept. 21 military parade in Sana’a.
Houthi mines have caused significant harm to the Yemeni Coastguard involved in mine clearance operations, some commercial shipping, and local fishing communities. Moored mines break loose and floating mines drift ashore or get caught in fishing nets, resulting in deadly incidents. As the Red Sea’s currents and winds follow seasonal monsoons, blowing south during summer and north in winter, Houthi naval mines can move big distances, causing casualties among fishing communities across the Red Sea littorals.
The Houthis’ decision so far to refrain from large-scale mining operations in the Red Sea chokepoints reflects the militia’s decision to primarily target commercial ships owned by Israeli, U.S., and U.K. shipping companies, as well as merchant vessels flagged by other countries that have links, through ownership or port calls, to Israel.
The tactical specifications of naval mines in the Houthi inventory do not allow for precise targeting of vessels. Therefore, using sea mines in a major way could potentially damage ships heading to ports in Houthi-controlled territories or with links to countries with no open quarrels with the armed group, such as Iran, China, and Russia.
Nevertheless, Houthi mines represent a considerable potential threat to navigation in and around the Red Sea. On October 27, 2024, Houthi-affiliated media released propaganda videos of a recent military drill simulating coastal combat operations with sea mines, underscoring the active role of submerged explosives in the armed group’s warfare doctrine. If the Gaza and Lebanon wars continue and hostility between Israel and Iran also escalates, the Houthis might adjust their tactics and inject sea mines into the security equation.
In anticipation of such a shift, some regional countries have sought to develop mine countermeasures capabilities. The Saudi Navy has three Sandown-class minehunters in active service. The United Arab Emirates currently deploys a Frankenthal-class minehunter. A second minehunter was severely damaged by a Houthi attack in 2017 and is believed to have been de-commissioned.
The U.S. Navy, based in Bahrain, runs Task Force 52, a force specialized in mine warfare operations that includes four Avenger-Class vessels and MH-53E Sea Dragon rotorcrafts. The 9th Mine Countermeasures Squadron, a squadron of the U.K.’s Royal Navy, comprises three vessels and a support ship, also stationed in Bahrain.
The U.S. and Britain hold bilateral and multilateral drills in mine warfare and explosive ordinance disposal simulations to test their capacity to respond to sea mines incidents and bolster interoperability. However, efforts to strengthen mine countermeasure readiness rarely top security priorities, resulting in a lack of platforms and resources.
Mine hunting and clearing operations are a high-cost and time-intensive endeavor. Made of wood and fiberglass to reduce their signature, the mine-clearing ships are vulnerable to targeting by drones and rockets fired from Houthi-controlled territories in Yemen.
The fact that the Houthi naval attack pattern has significantly evolved over the past ten months suggests that the militia has the political will and capability to adjust its tactics to evolving conditions in the maritime battlespace. Regional and extra-regional countries would be prudent to increase their mine countermeasures capabilities to prepare.
Leonardo Jacopo Maria Mazzucco is an independent research analyst who focuses on the security and defense affairs of the Persian Gulf region. He is also an analyst at Gulf State Analytics, a Washington-based geopolitical risk consultancy. Leonardo tweets at @mazz_Leonardo.
Editor’s Note: Leonardo Jacopo Maria Mazzucco is a specialist on maritime operations in the Persian Gulf and nearby waters. He has previously written for Stimson about the Saudi navy and about arms and drug trafficking.
By Barbara Slavin, Distinguished Fellow, Middle East Perspectives
In 1984, a sea mines act of sabotage, whose attribution remains debated, disrupted navigation across the Red Sea’s gateways — the Suez Canal and the Bab el-Mandeb Strait. In response to regional requests, a U.S.-led coalition conducted countermeasure operations, restoring safe shipping in the strategic waterway connecting the Mediterranean Sea and the Indian Ocean.
Forty years later, naval mines still represent a potential threat to seaborne trade, energy products, and underwater digital infrastructures in and around the Red Sea. The Yemeni insurgent group Ansar Allah, commonly known as the Houthis, has held free navigation in the region hostage since mid-November 2023, launching hundreds of missile, drone, and boat swarm attacks on commercial shipping in support of Palestinians fighting Israelis in Gaza. If the war continues, the Houthis might also resort to laying mines to try to close the Bab el-Mandeb or to attack international shipping in the Red Sea.
Throughout history, actors with limited naval capabilities confronting more powerful adversaries have used sea mines to level the playing field. Both Iran and Iraq used mines during their 1980-88 war. After Iraq invaded Kuwait in 1990, it laid over 1,000 mines off Kuwait to prevent a U.S.-led coalition from launching an amphibious landing operation.
Naval mines provide a strategic advantage in the defense doctrine of small states and non-state actors. They are highly regarded as relatively affordable and can be fielded without the support of advanced naval platforms. They impose disproportionate costs on an adversary determined or compelled to clear mine-infested waters, thereby shifting the power dynamics.
Moored mines, anchored on the seabed through cables and floating beneath the surface, play an anti-access function to protect ports and harbors. Drifting mines perform an area denial role as they can travel significant distances from their initial sowing carried by ocean currents.
For much of its history, the Houthi movement focused on projecting force on land. From Sa’dah, a mountainous territory bordering Saudi Arabia, the Houthis used guerrilla warfare in localized clashes with then-Yemeni President Ali Abdullah Saleh’s forces in the 2000s in what became known as the Sa’dah wars.
After the Houthis took over Yemen’s capital of Sana’a in September 2014, their military campaign shifted west and south to the littoral areas overlooking the Red Sea and the Bab-El-Mandeb. The Houthi capture of the port of Hodeida in November 2021 marked a significant turning point, extending the group’s control over large swaths of Yemen’s western coast and accessing the Yemeni Army’s stockpiles of weapons and naval assets. This enabled the Houthis to begin to weaponize the maritime domain.
The Houthis are no match for the U.S. and most Persian Gulf Arab countries on a ship-for-ship basis. Yet they have increasingly become a threat to seafarers in and around the Red Sea.
Since early 2017, the Houthis have sown hundreds of mines near Yemen’s Red Sea coasts to prevent Saudi-led forces from launching amphibious operations and seizing outposts crucial to Houthi defenses.
The Houthis have planted mines in shallow waters off major coastal cities, such as Mokha, Al Hodeida, and Midi, and around strategic islands, including Kamaran, the Hanish archipelago, and Buklan. Lacking purpose-built minelayers, the Houthis have used speed boats and fishing vessels to sow the mines.
Some were Soviet-era devices, suggesting that they originated from the Yemen Army’s ammunition stores. However, most are believed to be indigenously manufactured by the Houthis. A close resemblance between the more advanced mines and Iranian-made designs suggests technology transfers from Tehran.
The most basic devices include floating mines made from household gas cylinders filled with explosives and fitted with contact detonators. More sophisticated models are fixed on the seabed through an anchoring mechanism and equipped with contact or influence (magnetic or acoustic) detonators. The Houthi inventory also reportedly includes limpet mines, which attach to a ship’s hull with magnets.
The Yemeni insurgent group has made no secret of its expanding arsenal, with new systems trumpeted by Houthi-affiliated media and displayed at a Sept. 21 military parade in Sana’a.
Houthi mines have caused significant harm to the Yemeni Coastguard involved in mine clearance operations, some commercial shipping, and local fishing communities. Moored mines break loose and floating mines drift ashore or get caught in fishing nets, resulting in deadly incidents. As the Red Sea’s currents and winds follow seasonal monsoons, blowing south during summer and north in winter, Houthi naval mines can move big distances, causing casualties among fishing communities across the Red Sea littorals.
The Houthis’ decision so far to refrain from large-scale mining operations in the Red Sea chokepoints reflects the militia’s decision to primarily target commercial ships owned by Israeli, U.S., and U.K. shipping companies, as well as merchant vessels flagged by other countries that have links, through ownership or port calls, to Israel.
The tactical specifications of naval mines in the Houthi inventory do not allow for precise targeting of vessels. Therefore, using sea mines in a major way could potentially damage ships heading to ports in Houthi-controlled territories or with links to countries with no open quarrels with the armed group, such as Iran, China, and Russia.
Nevertheless, Houthi mines represent a considerable potential threat to navigation in and around the Red Sea. On October 27, 2024, Houthi-affiliated media released propaganda videos of a recent military drill simulating coastal combat operations with sea mines, underscoring the active role of submerged explosives in the armed group’s warfare doctrine. If the Gaza and Lebanon wars continue and hostility between Israel and Iran also escalates, the Houthis might adjust their tactics and inject sea mines into the security equation.
In anticipation of such a shift, some regional countries have sought to develop mine countermeasures capabilities. The Saudi Navy has three Sandown-class minehunters in active service. The United Arab Emirates currently deploys a Frankenthal-class minehunter. A second minehunter was severely damaged by a Houthi attack in 2017 and is believed to have been de-commissioned.
The U.S. Navy, based in Bahrain, runs Task Force 52, a force specialized in mine warfare operations that includes four Avenger-Class vessels and MH-53E Sea Dragon rotorcrafts. The 9th Mine Countermeasures Squadron, a squadron of the U.K.’s Royal Navy, comprises three vessels and a support ship, also stationed in Bahrain.
The U.S. and Britain hold bilateral and multilateral drills in mine warfare and explosive ordinance disposal simulations to test their capacity to respond to sea mines incidents and bolster interoperability. However, efforts to strengthen mine countermeasure readiness rarely top security priorities, resulting in a lack of platforms and resources.
Mine hunting and clearing operations are a high-cost and time-intensive endeavor. Made of wood and fiberglass to reduce their signature, the mine-clearing ships are vulnerable to targeting by drones and rockets fired from Houthi-controlled territories in Yemen.
The fact that the Houthi naval attack pattern has significantly evolved over the past ten months suggests that the militia has the political will and capability to adjust its tactics to evolving conditions in the maritime battlespace. Regional and extra-regional countries would be prudent to increase their mine countermeasures capabilities to prepare.
Leonardo Jacopo Maria Mazzucco is an independent research analyst who focuses on the security and defense affairs of the Persian Gulf region. He is also an analyst at Gulf State Analytics, a Washington-based geopolitical risk consultancy. Leonardo tweets at @mazz_Leonardo.
