Militant group Abu Sayyaf (ASG) has conducted frequent kidnap for ransom attacks in the Sulu and Celebes Seas since March 2016, says a report by Protection Vessels International Ltd.
Islamic State-affiliated ASG has successfully extracted millions of dollars' worth of ransom payments for individual releases and has decapitated several hostages when ransom demands have not been met.
In November, ASG shifted towards targeting commercial vessels and successfully abducted six crew members from a bulk carrier.
Armed robberies have grown increasingly violent in Indonesian waters in 2016 with robbers assaulting crew members who attempt to stop them.
The Sulu and Celebes Seas off the eastern coast of the island of Borneo have seen a significant spike in hijackings and kidnappings for ransom since March 2016. Philippine Islamist group ASG, which is based in the Jolo and Basilan islands of the Sulu Sea, has claimed the majority of the attacks.
Masked gunmen have typically targeted slow-moving tugs and fishing boats although in recent weeks they have demonstrated the capability to successfully kidnap crew from underway commercial vessels between Borneo and the Philippines, heightening the risk to global shipping in the region.
On 10 November, 10 gunmen boarded a Vietnam-flagged bulk carrier, Royal 16, 8.3 nm southeast of Coco Island in the Basilan Strait, and kidnapped six crew members including the master and chief mate.
In November, the group also kidnapped a German national and killed another on a yacht off Sulu, and has also launched failed attacks against a chemical tanker off Sibutu Island and a bulk carrier northwest of Cap Island, indicating a sustained threat to commercial vessels. Vessels have managed to deter attacks through a combination of vessel hardening measures and evasive manoeuvres.
Maritime authorities in the region have been slow to respond to the attacks and have failed to secure the Sulu and Celebes Seas, despite repeated pledges to cooperate more closely and conduct joint patrols, leaving the waters vulnerable to future attacks.
Even basic measures such as allowing Indonesian, Malaysian and Philippine maritime forces to pursue suspected criminals into each other's waters were only agreed in August, months after the attacks first began in March. The abductions in the region look set to continue for the foreseeable future as ASG is under persistent pressure to gain ransom funds to finance its battles with Philippine government forces.
More generally, violent robberies against vessels off Indonesia have increased since the second quarter of 2016, after a lull in reported incidents in the first three months of the year.
While in the majority of incidents robbers have been easily deterred there has been a notable increase in violent incidents with assailants holding crew hostage at gunpoint while equipment and ship's stores have been stolen. Robbers have typically targeted vessels anchored at Dumai and Batam anchorages, although there is also precedent for underway vessels to be targeted.