The incident involving the 107,113-dwt Aframax Rio (built 2004) took place last week, but details have only just emerged.
Details of the attack, which took place off Nipah Anchorage, feature in the latest piracy report from security consultants AKE Maritime.
The Panama-flagged tanker was boarded by four armed robbers, but they retreated to their boat when the alarm was raised.
A subsequent search of the vessel found that no items had been stolen, while the ship’s complement were all crew safe.
The Japanese-built crude oil tanker is operated by Singapore-based Navig8 Pte as part of its V8 aframax pool.
Shipowners operating in Indonesia face one of the highest chances of a piracy attack in the world where around one-third of sea crimes occur.
Almost all attacks are opportunistic ‘smash and grab’ type robberies on vessels in port or at anchor, according to AKE intelligence analyst Rory Lamrock.
