Maritime crimes, including piracy, increased 22 percent in Southeast Asia during the first six months of this year over the same period in 2014, according to a report.

In the first half of this year, there were 120 reports of piracy and maritime crimes in Southeast Asia, an increase of 22 percent over the same period in 2014, according to Dryad Maritime, a British maritime intelligence and operations company.

Twelve of the reported incidents involved the hijacking of vessels, three more than during the same period last year.

Dryad said the arrest of two sets of hijackers this year will likely result in a slowdown in the number hijacking of small product tankers but that would most likely be a temporary situation.

"Our latest figures for piracy and maritime crime highlight the uncertain, chaotic and, sometimes, dangerous nature of global maritime operations," said Ian Millen, chief operating officer of Dryad Maritime.

"Southeast Asia is in urgent need of a joined-up effort to tackle the criminal gangs who are hijacking small regional tankers and robbing other vessels in transit, with the Singapore Strait being in dire need of some effective, coordinated action."