Piracy incidents in the first six months of the year rose to 134, according to the International Maritime Bureau’s Piracy Reporting Centre.

The figure, up from 116 in the corresponding period last year, includes 106 vessels boarded, 15 attempted attacks and 13 hijacks.

The number of incidents in southeast Asia remains a concern, with five small tankers hijacked in the second quarter. There have been 11 hijacks in the region this year.

Indonesia dominates the statistics, with 54 reports, although many relate to low-level, opportunistic thefts. Indonesian pirates are usually armed with guns, knives or machetes and generally attack at night. If they are seen and an alarm is sounded, they usually flee without confronting crews.

Vietnam accounted for 13 incidents, while Malaysia, Nigeria and Bangladesh each reported 11. There were no reported incidents off the coast of Somalia, a previous hotspot, but the bureau warns against complacency.

“Somali pirates still have the capability and capacity to carry out attacks,” it says.

“[We believe] that a single successful hijacking of a merchant vessel will rekindle the Somali pirates’ passion to resume piracy efforts.”

As of June 30, Somali pirates continue to hold 29 crew members for ransom.