Piracy and armed robbery on the world’s seas has not seen significant increases compared to 2014, the International Chamber of Commerce (ICC) International Maritime Bureau’s (IMB) annual piracy report has found.

IMB’s Piracy Reporting Centre (IMB PRC) recorded a total 246 incidents in 2015, just one more than in 2014. As the graph below shows, the report also records a fall in the number of ships hijacked and crew captured.

A total of 15 vessels were hijacked in 2015, down from 21 in 2014, while 271 hostages were held on their ships, compared with 442 in 2014. No hijackings were reported in the last quarter of 2015. According to IMB, one key factor in this recent global reduction was the drop in attacks against small fuel tankers around Southeast Asia’s coasts, the last of which occurred in August 2015.

“IMB particularly commends the robust actions taken by the Indonesian and Malaysian authorities in the arrest and prosecution of two gangs that hijacked tankers. We also applaud the subsequent arrest of some of the alleged masterminds,” says Pottengal Mukundan, director of IMB.

On the other hand, the number of vessels boarded rose by 11% to 203, one ship was fired at, and a further 27 attacks were thwarted. Mukundan urges shipmasters to maintain strict anti-piracy and robbery watches, particularly in Southeast Asia, the area that still accounts for most of the world’s incidents.

In Vietnam alone, incidents surged from seven in 2014 to 27 in 2015. The main cause is low-level theft against vessels anchored in the country, with 15 reports from around the port of Vung Tau alone. IMB considers this rise on moving vessels as a cause for concern as it increases potential risks to the vessels and their crew. Four incidents were also recorded in China in December 2015, the first in a long time.

According to the report, Nigeria also remains a hotspot for violent piracy and armed robbery. IMB received reports of 14 incidents, with nine vessels boarded, although many attacks are believed to go unrecorded.

On the positive side, the once insidious Somali pirates have all but withered, with no Somali-based attacks reported in 2015. IMB however warns vessels transiting the Gulf of Aden and the Indian Ocean to remain vigilant in that area. “Somalia remains a fragile state, and the potential for an attack remains high,” explains Mukundan. “It will only take one successful hijacking to undo all that has been done, and rekindle this criminal activity.”