KUALA LUMPUR (AFP) - Piracy on the high seas fell last year to an eight-year low worldwide but the number of successful ship hijackings increased due to rising numbers of attacks in the waters off South-east Asia, a piracy watchdog said on Wednesday.

The International Maritime Bureau said in an annual report that 245 pirate attacks were recorded globally in 2014, down from 264 the year before, and nearly half of the 445 reported in 2010 when piracy off Somalia was raging.

Global piracy incidents have tumbled since then due to a multi-national naval patrol effort launched off East Africa, as well as improved onboard security.

However, the seas off South-east Asia, particularly the waterways between Indonesia, Singapore and Malaysia, have steadily emerged as a new hotspot, with attacks on small tankers rising.

Worldwide, 21 vessels were hijacked last year - 16 of which were in South-east Asia - compared to 12 in 2013, according to the report released by the IMB's Kuala Lumpur-based piracy monitoring centre.

Pirates killed four crew members, injured 13 and kidnapped nine from their vessels globally, it said.

"The global increase in hijackings is due to a rise in attacks against coastal tankers in Southeast Asia," IMB Director Pottengal Mukundan said in a statement accompanying the report.

"Gangs of armed thieves have attacked small tankers in the region for their cargoes, many looking specifically for marine diesel and gas oil to steal and then sell." The South-east Asian attacks made up the bulk of incidents reported globally.

The region saw 141 piracy incidents - the vast majority of them in Indonesian waters - in 2014. These included hijackings, boardings and attempted attacks that were thwarted.

That compares to 128 total in incidents in the region in 2013.

South-east Asia is home to vital shipping lanes such as the South China Sea and the Malacca Strait separating Malaysia and Indonesia, through which one-third of global trade passes.