File Photo: A general view of the Berbera Port on the Gulf of Aden. AFP
The United Kingdom Maritime Trade Operations (UKMTO) said the incident took place 65 nautical miles south of Mukalla, a major city on Yemen's south coast.
"Military authorities have reported that the vessel was boarded by unauthorised personnel whilst transiting east in the Gulf of Aden," the agency posted on X.
Yemen's coast guard said the ship, a chemical tanker named the Asana, was captured by "a group of Somali pirates" and was heading southeast, towards Somalia.
Ambrey, a maritime security company, said the Tanzania-flagged ship did not have an armed security team aboard, and added that a South Korean navy "vessel was en route to the tanker to provide assistance".
The Maritime Security Centre Indian Ocean (MSCIO), the information service for the EU's anti-piracy naval mission in the area, said it was "investigating the incident and monitoring the vessel".
The shipping route linking Yemen and the Horn of Africa, which connects the Indian Ocean to the Red Sea, is one of the world's busiest maritime corridors. However, the US-Israel war against Iran has significantly disrupted shipping traffic, particularly through the Strait of Hormuz.
The Joint Maritime Information Centre (JMIC), run by a massive 47-nation coalition deployed in the northern Indian Ocean to fight the Horn of Africa's longtime pirate menace, raised its alert level to "severe" in early May, its second-highest.
It came after a series of attacks by Somali pirates who seized several vessels off the coast of Yemen and off the coast of Puntland, a state in northeastern Somalia.
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