Authorities in Indonesia's Riau Islands have arrested 11 suspects accused of carrying out a series of armed robberies on foreign cargo vessels in border waters since 2017. Police are also pursuing three other active pirate groups operating in the area.

The arrests were carried out by the Ditpolairud (Water and Air Police Unit) of the Riau Islands Police, based on tips from the public and the Singapore-based International Maritime Bureau (IMB).

According to police reports, the suspects were apprehended near Nipah and the Phillip Channel in the Karimun area while stealing spare parts from a foreign vessel named “Elizabeth.” The region is considered vulnerable because vessels navigating through the Nipah Strait are required to slow down to between 0 and 5 knots — a condition exploited by pirates to target slow-moving ships.

Following reports of suspicious maritime activity, authorities began monitoring and patrolling the area. On July 9, a marine police team intercepted a boat with a 72-horsepower Yamaha engine near a foreign cargo ship.

Eight men were arrested on board. Investigations revealed that the suspects used a 10-meter-long bamboo pole to hook ropes onto passing ships and climb aboard. Some had heavily calloused feet from repeatedly boarding ships barefoot at night. Their primary targets were engine spare parts, which could be resold in Jakarta for profit — with some thefts reportedly earning up to $6,000 per operation.

Further investigation led to the arrest of three additional suspects. One was identified as the coordinator of the robberies, another was found in possession of four packets of crystal meth, and the third was responsible for delivering stolen goods to a contact in Jakarta.

Police stated that the gang used standard online ship-tracking websites to identify slow-moving vessels. Before each robbery, members reportedly used crystal meth to boost confidence and suppress fear. According to Handono Subiakto, an officer with the Riau Islands Marine Police, the drugs made them bolder, to the point where they were willing to jump into the sea when pursued or threatened.

Although no firearms were found during the arrests, police did seize a homemade air rifle used to intimidate crew members. The weapon was described as having a “high explosion type” effect. Investigators suspect the group may have previously used homemade firearms, though none were in their possession during the operation.

Along with the arrests, authorities confiscated various pieces of evidence: a barge, three mobile phones, four packets of crystal meth, an air rifle, and five boxes of stolen spare parts.

The suspects face multiple charges under Indonesian law, including aggravated theft under Article 363 of the Penal Code, fencing and selling stolen goods under Article 480, drug-related offenses under Articles 112 and 197, and criminal conspiracy under Article 55.

Based on information gathered during the investigation, police also confirmed the existence of three other active pirate groups in the region — referred to as Group J, Group O, and Group JO. Some members are repeat offenders with prior arrests for similar crimes. One of the arrested suspects, identified as S, is believed to have had previous associations with both Group J and Group O.

According to the ICC International Maritime Bureau, 57 incidents of armed robbery were reported in the region during the first half of 2025 — nearly four times more than the 15 incidents reported during the same period last year.

The Phillip Channel, located south of Singapore’s Jurong Island, remains a hotspot for such crimes. The sharp turns in the channel force ships to reduce speed, making them more vulnerable to attacks by criminal groups.