KUALA LUMPUR - A spate of daring high-seas attacks off Southeast Asia is stoking fears that its vital shipping lanes could once again become a hotspot for piracy unless regional powers act fast.
For centuries, pirates were the scourge of the Malacca Strait - the strategic channel between Indonesia, Malaysia, and Singapore through which a third of global trade now passes.
They were largely put out of business about five years ago by stepped-up patrols.
But several tankers or cargo ships have been attacked in Southeast Asian waters since April, with pirates hijacking the vessels before siphoning off hundreds of tonnes of valuable fuel or oil.
The increasing booty of oil and other cargo floating through local seaways appears to be drawing in new players, possibly underpinned by organised criminal syndicates, according to anti-piracy experts.
"Everybody is concerned about these latest attacks because they know it will worsen," said Noel Choong, head of the International Maritime Bureau's (IMB) piracy reporting centre in Malaysia.
"It will become rampant again and you will have a hard time stopping it. That's how Somalia got started." In recent years, global concern over piracy has focused on attacks by trigger-happy Somali pirates off East Africa.
An international naval effort has virtually stamped out that threat - but in the meantime, Southeast Asian piracy attacks have crept back up, increasing from 46 in 2009 to 128 last year, according to the IMB, and are on a similar pace for 2014.
Most are localised robbery attempts in Indonesia's vast waters for relatively small stakes, the IMB says. It adds that major lanes like the Malacca Straits remain safe, with only one attack this year.
Tens of thousands of ships pass through the strait annually.
Rich cargoes draw pirates
But the spurt of brazen incidents raises fears of a return to the frequent hijackings and kidnappings by mostly Indonesia-based armed pirates seen a decade ago, especially as successful piracy usually breeds more.
In one attack on May 28, the Thai tanker MT Orapin 4 was hijacked north of Indonesia's Bintan Island.
The pirates reportedly painted over its name, destroyed communications equipment and brought in a smaller tanker vessel to siphon off much of the ship's 3,700 metric tonne oil cargo. The vessel and crew were later released.
Similar incidents have been repeated, possibly indicating serial action by the same gangs.
The elaborate operations, say experts, suggest coordination with criminal syndicates organised enough to move such large cargoes to market.
"Maritime crime has always been an issue in the region, but we are seeing an increase in hijackings for cargo. The black market for marine gas oil is extremely lucrative," said David Rider, editor of the Maritime Security Review, who wrote recently that the new attacks had "taken everyone by surprise".
Southeast Asian piracy remains relatively benign compared to a decade ago. Pirates rarely carry guns, while taking hostages for ransom has stopped, said Choong.
But the lucrative stakes could lead to more attacks, with East and West Africa offering chilling cautionary examples.
The lust for tanker cargoes has turned waters near oil-rich Nigeria into the world's major area of piracy concern due to the often deadly shoot-first attacks by gun-toting pirates, Choong said.
Martin Sebastian, head of Malaysia's Centre for Maritime Security and Diplomacy, said growing Southeast Asian sea traffic complicates enforcement while offering increasingly enticing pickings.
"Where there is money, the pirates emerge," he said.
Call for stepped-up patrols
The IMB is urging regional authorities to beef up naval patrols, and recommending round-the-clock anti-piracy watches on vessels.
Some calls have emerged for armed private security on ships - but that's expensive, and in any case banned in Indonesian, Malaysian and Thai waters.
Piracy experts said the region is better-positioned today to snuff out any resurgence following the successful suppression of recent years.
An Indonesian navy spokesman said his country's forces are continuing to coordinate on patrols with its neighbours.
But pirates are also smarter, and are exploiting national sea boundaries and the limitations of regional naval forces to evade detection, said Bantarto Bandoro, a security expert at the Indonesian Defence University.
"They have good information on who is being monitored, where the sea is being monitored - and their intelligence gathering is improving," he said, adding that international coordination remains insufficient.
Southeast Asia has a checkered history of cooperation on various issues, and combating resurgent piracy will ultimately require close coordination to root out onshore criminal gangs believed to be fuelling it, Sebastian said.
Regional economies will be burdened with extra costs, including higher shipping insurance rates and more spending on security assets, "if we don't nip it in the bud", he warned.