Skiff chases tanker 75 nautical miles east of Yemen's Aden

A skiff pursued and attempted to intercept a westbound tanker 75 nautical miles east of Aden, Yemen, the UK Maritime Trade Operations (UKMTO) reported on September 17.

The approach is the latest in a run of incidents that has made the Gulf of Aden the most active piracy zone in over a month. The International Maritime Organization has logged at least 15 attacks off Somalia and in the Gulf of Aden this year, the highest tally since 2013, and four tankers, the Honour 25, Eureka, Asana and Seamull, remain in the hands of Somali pirate groups.

UKMTO, the Royal Navy-run body that collects reports from merchant shipping in the region, said the incident took place at 1359 UTC and that authorities were investigating.

The British group advised vessels to transit with caution and to report suspicious activity. No damage or injuries were reported, and the tanker was not named.

The alert came six days after six armed men boarded the Saint Vincent and the Grenadines-flagged tanker Glamour 38 nautical miles off the Yemeni coast on September 11.

The crew shut down the vessel and locked themselves in the citadel until a Japanese warship and helicopters arrived, at which point the attackers fled.

The cargo ship Sward, hijacked in April with 17 crew on board, was released on September 11 after a ransom payment. A ransom of $1.5mn was paid earlier this year for a Chinese vessel held from January to March.

The Seamull, also known as Sibu 1, was seized 136 nautical miles east of Al Mukalla on August 20 by six armed men and diverted towards Somalia.

In July, six skiffs approached a Marshall Islands-flagged tanker 50 nautical miles south of Aden and withdrew only after the ship's armed guards fired warning shots, according to British security firm Ambrey.

The Joint Maritime Information Centre currently rates the threat to shipping off Aden as substantial and off the Somali coast as moderate, with naval escorts stretched by the parallel crisis in the Strait of Hormuz, where a fully laden tanker was struck by a projectile and set ablaze on September 13.