NO: DELENG / 2017 / 70663
official media partner of national maritime foundation
Lars H. Bergqvist Master Mariner, Norwegian Merchant Marine Lieutenant, Royal Swedish Naval Reserve.
By Sea and Coast | 04/01/2021

Asymmetrical warfare in the Middle East against merchant shipping

Oil tanker explosions in the Red Sea and the Arabian Sea are occurring on an alarming regularly basis. The latest incident happened in the Port of Jeddah (KSA) to BW Rhine, a 76,580 DWT tanker belonging to the BW Group. This attack happened just a few weeks after the tanker M/T Agrari was attacked in a similiar fashion near Shuqaiq, another Red Sea port in Saudi Arabia. Fortunately, in both cases, there was no injure to the crew or a large oil spill.

The conflict

The attacks on shipping are mainly linked to the Yemeni civil war. Broadly, it is conflict between the Yemeni government and the Houthi rebels, which in the larger picture is a proxy war in the Middle East between Iran on one side and Saudi Arabia and the Gulf States on the other. In simple terms, it is a tug of war between Shia Muslims and Sunni Muslims.

Also USA, UK, Turkey, France and Israel are involved the conflict, although in a more covert role.

The incidents

From maritime attacks that were rather limited in location, close to Houthi held territory, incidents now stretch from the middle of the Red Sea to the northern part of Gulf of Oman.

The attacks are mainly directed towards vessels that have some kind of connection to Saudi Arabia or the United Arab Emirates or are visiting ports of these countries, like the recent attack in Jeddah or the attacks on four tankers at Fujairah anchorage in the spring of 2019. However, also Iranian vessels have been victims of explosions and the belligerent actors can be hard to identify among the usual suspects of state actors, non-state actors, rebels, terrorists and pirates.

Yemen became infamous for maritime terrorist attacks about 20 years ago, when first USS Cole was attacked in the port of Aden and two years later when the French tanker M/T Limburg was attacked when approaching the loading bouy at Ash Shihr oil terminal.

The incidents were rather straight forward and easy to identify; the mode of attack (suicide bombers in waterborne improvised explosive devices), an organisation that claimed responsibility (Al Qaeda) and the motive (to harm nations that were considered enemies). After the Limburg attack, Osama bin Laden issued following statement; “By exploding the oil tanker in Yemen, the holy warriors hit the umbilical cord and lifeline of the crusader community, reminding the enemy of the heavy cost of blood and the gravity of losses they will pay as a price for their continued aggression on our community and looting of our wealth.”

Fortunately, until the start of the Yemeni civil war late 2014, the Red Sea and the Arabian Sea were very much spared from the menace of maritime terrorism.(1) However, merchant ships were still in harm's way during transit of the Gulf of Aden and Western Indian Ocean due to the ferocity of Somali pirates.

Although the war started in 2014, it took about two years before the Houthi rebels got a maritime capacity to attack seagoing crafts. The incidents described below is by no means an exhaustive list but it gives an overview over how the maritime security situation has developed.

In October 2016 a missile was fired from rebel held territory and hit the United Arab Emirates catamaran Swift when she was transiting the narrow strait of Bab el Mandeb. UAE claimed it was a civilian vessel carrying aid, whereas the Houthi rebels stated that it was a naval vessel. Due to the incident, US Navy dispatched two destroyers (USS Mason and USS Nitze) and the amphibious transport dock USS Ponce to the area. Subsequently, USS Mason and USS Ponce came under attack from land-based anti-ship missiles, but without being hit. As a response, USS Nitze launched Tomahawk cruise missiles destroying radar stations ashore used for the initial attack.

As an example of the complex and blurred situation, can the incident of the LNG-tanker Galicia Spirit highlight. The attack took place near Bab el Mandeb on the same month, October 2016. But this was a low tech seaborne assault, with a skiff that for unknown reasons exploded 20 meters before reaching the topside of the tanker. Nobody ever claimed responsibility for the attack.

Another spectacular incident was the missile attack on M/S Ince Inebolu, a Turkish-flagged bulk carrier. With a cargo of wheat, the bulker was proceeding to the Red Sea port Salif in Yemen when she was hit. Fortunately, only structural damages to a ballast tank was the result of the attack.

In January 2017, there was a change of modus operandi when a Saudi frigate was hit west of the rebel held port of Hudaydah. The frigate was hit in the stern by an explosive device, and two KSA sailors were killed. The coalition forces claimed that “suicide boats” had been used, but more likely a remotely controlled water borne improvised explosion device had been used.

In the May 2019, the conflict in Yemen was brought to neighbouring states when four tankers were attacked at Fujairah anchorage. It was a well performed military mission that slightly damaged the vessels, without causing any injure to the crew or oil pollution. Fujairah is a very busy anchorage with as many as 100 vessels at anchor at any time. To pin point the vessels, that all had some connection to the coalition forces, indicates good planning and professionalism, although the attack was facilitated by AIS that was transmitting data on each vessel.(2) Most observers came to the conclusion that limpet mines had been used, attached by divers or sailors on small boats.

About a month after the Fujairah incident, another spectacular incident took place far away from Yemen when two loaded tankers were attacked in the Gulf of Oman, Front Altair and Kokuka Courageous. Also in these incidents, it was believed that limpet mines had been used.

That the Red Sea is a treacherous waterway could also the Iranians testify to. The Islamic Republic claimed in the autumn of 2019 that three Iranian tankers had been targeted in a six-month period. However, only one incident, the explosion on the tanker Sabity has been confirmed. The vessel, in loaded condition and under way off the Saudi coast near Jeddah, was most likely hit by missiles.

The weapons

The Houthi rebels have used sophisticated weapons like anti-ship missiles, but they have also been accused of using rudimentary weapons, like drifting naval mines. The waterborne improvised explosive device (WBIED) can, as the name indicates, also be considered unsophisticated. However, the WBIEDs have become more advanced by being remotely controlled.

During the 2006 Lebanon war an anti-ship missiles was successfully used by Hezbollah against the Israeli frigate INS Hanit. That non-state actors can use sophisticated weapons have further been highlighted during the conflict in Yemen. Nonetheless, a weapon platform is needed to get close to the target, or the target needs to be close to shore, in order for missiles to be effective. Missiles can be defined as belonging to conventional warfare, that can be met with conventional countermeasures, like in the case with USS Mason and USS Nitze.

Although that there have been many warnings about drifting sea mines, there are no confirmed incidents. It is hardly likely that any of the warring parties in the conflict will use such imprecise method of naval warfare. A parting wire may cause an anchored mine to float to the surface and start drifting, but that is not a part of any modus operandi. Notwithstanding, off the port of Mohka a Yemeni coast guard ship struck a submerged mine that was anchored. 

The mine that allegedly has been causing most damage in the conflict is the limpet mine. Both at Fujariah anchorage incident and in the Gulf of Oman incident the conclusion has been that limpet mines have been used. It is a legendary method, perfected by Decima Flottiglia MAS, an Italian commando frogman unit that was sinking allied ships in the Mediterranean during the Second World War. However, it is a rather refined method that needs highly skilled and trained operators.

Remotely Controlled Waterborne Improvised Explosive Devices (RCWBIED) are probably the most effective method when attacking naval or merchant ships. As the weapon platform becomes more and more advanced, maybe “improvised” should be dropped, and renamed to Armed Maritime Drone. It should not be ruled out that even Unmanned Underwater Vehicles (UUVs) have been used.

Unmanned Aerial Vehicles (UAVs), or drones, laden with explosives have been used by Houthi rebels against land targets in Saudi Arabia.


The defence

Commonly when non-state actors are fighting wars, asymmetrical warfare is used to a large extent by the Houthis. As experience from many wars shows, it is difficult to fight insurgents with conventional armed forces. The famous Lawrence of Arabia wrote in his book Seven Pillars of Wisdom that “Making war upon rebellion was messy and slow, like eating soup with a knife.” Hence, conventional war ships are maybe not best platforms to combat waterborne guerrilla fighters.

Navies from many nations are patrolling in the conflict area, some on an individual basis, some organized in units like the Combined Maritime Forces. However, as with the case of Somali piracy, the naval ships are too few in order to give a proper protection in the high risk area (HRA).

In ports, the port authorities are obliged by the ISPS code to provide security in ports. That ports are failing in their obligations are the recent attacks in Jeddah and Shuqaiq an example of.

In consequence, merchant ships are very much left alone to protect themselves from terrorist attacks. The ISPS code should be followed and a risk analysis conducted. Fortunately, there are some excellent guidelines that have been developed during the last decade.

BMP5 - Best Management Practises To Deter Piracy And Enhance Maritime Security In The red Sea, Gulf Of Aden, Indian Ocean And Arabian Sea is, as the title indicates, on its fifth edition. Is a document vital to follow when a Captain, SSO and CSO are planning and executing a voyage through the HRA.

The Oil Companies International Marine Forum (OCIMF) has produced Ship Security Bridge Vulnerability Study, with recommendations about ship hardening.

The International Maritime Security Construct (IMSC), a US led consortium of countries tasked with maintaining maritime security in the Persian Gulf, Gulf of Oman, Gulf of Aden and Southern Red Sea, has issued Bridge Reference Cards with guidelines how to react to hostile situations.

Combined Maritime Forces (CMF), which is another multi-national naval organisation, has establish the Maritime Security Transit Corridor (MSTC) for safe passage of southern Red Sea, Bab el Mandeb and Gulf of Aden.

The shipping industry has a very informative website ( where the above mentioned documents can be found, together with other important information concerning maritime security.


1) Before 2014 following terrorist incidents occurred;

- In July 2010, the Japanese owned very large crude oil carrier M Star experienced an explosion when transiting the Strait of Hormuz. Although no craft was sighted, the explosion made a large dent in the hull, and parts of accommodation were slightly damaged. After two days, the terrorist group Brigades of Abdullah Azzam claimed responsibility for the attack.

- In August 2013, due to high level of activities by Al Qaeda affiliated groups in Yemen, the Government of United Kingdom raised the ISPS security level to level 3 for British flagged ships in Yemeni territorial waters. Indeed a serious situation, since an elevation to level 3 was unprecedented since the ISPS code was introduced in 2004.

- In September 2013, while on transit in the Suez Canal, the Chinese owned container vessel Cosca Asia was hit by a rocket propelled grenade. The ship sustained only minor damages, and there were no casualties. An Islamist group named Al-Furqan claimed responsibility for the attack.

2) Regarding the maritime security aspect to keep AIS on see following article.

#Sea and coast