EIGHT men armed with pistols and machetes boarded the Orkim Harmony, a tanker, in the early evening of June 11th. Carrying 6,000 tonnes of petrol—worth more than $5m at market prices—the ship was nearing the end of a voyage around the southern tip of Malaysia, from Malacca on the country’s west coast to Kuantan Port on its eastern one. The pirates restrained the crew and scrubbed three letters from the hull, crudely disguising the vessel with a new name, Kim Harmon. Then they headed north towards Cambodia, in search of a friendly port in which to siphon off her liquid cargo. When the ship was finally spotted seven days later, the hijackers warned away security forces by threatening to harm the hostages, then slipped away in a life boat with whatever loot they could grab. The crew escaped injury except for the cook, who was airlifted to hospital after being shot in the thigh. The attack on the Orkim Harmony was the latest in a spate of hijackings in South-East Asian seas, where the narrow straits separating Singapore and Malaysia from Indonesia provide passage for about one-third of the world’s shipping. Fifteen hijackings took place in 2014, up from only a handful the year before, according to the International Maritime Bureau; there have been nine in the past six months alone. These incidents are the most alarming symptom of a regional uptick in piracy, ranging from petty thefts in ports to more daring heists at sea. With the once-perilous waters around Somalia now calmed by an international effort, South-East Asia has regained an old reputation as the region worst-afflicted by piracy in the world.

Ten years ago South-East Asian nations appeared to have pirates on the run, thanks in part to co-ordinated naval patrols in the Strait of Malacca, off Malaysia’s south-west coast. But since then the problem has shifted eastward. Recent incidents have been taking place nearer to Singaporean waters in busy channels that allow pirates to hide in plain sight; as well as in the wilder, south-western corner of the South China Sea (see map). Unlike Somali pirates, who aimed to kidnap and ransom crew members—and often the ship itself—South-East Asian hijackers hope to steal petrol, palm oil and chemicals from small, slow-moving tankers, and almost always release the ship and crew when the theft is complete. Another danger is gangs who try to board and escape vessels undetected, pilfering goodies such as cash, engine parts and computers.

At present these crimes affect only a fraction of the 120,000 or so ships which sail near the strait each year. But seamen fret that the attacks are getting more violent, and the use of firearms more frequent. A Vietnamese sailor shot in the head during a botched hijacking last December was one of three South-East Asians killed by pirates in 2014. Even petty thieves can cause accidents if they attempt to board in congested waterways, says Philip Belcher of Intertanko, an association of tanker owners. “It’s like someone climbing into your boot while you’re driving down a motorway,” he says. A big worry is that insurers will raise premiums for ships in the strait, as they briefly did in 2005.

Shipowners gripe that complacent governments have been reducing coastal patrols. Some have accused ReCAAP—an outfit which helps to co-ordinate Asian governments’ responses to piracy—of downplaying the latest spike, perhaps to spare countries from embarrassment (ReCAAP has suggested, not unreasonably, that a portion of the recorded increase may be the result of better reporting). Merchants want regional navies to beef up anti-piracy operations.

Bigwigs from Indonesia, Singapore and Malaysia say they are discussing this. But any sallies into the South China Sea could be controversial while tensions are heightened by China’s territorial claims there. Lingering animosities between the three South-East Asian countries already hamper operations closer to home, by preventing navy boats from pursuing pirates who flee into neighbours’ waters. Even information-sharing is sensitive: Malaysia and Indonesia have not joined ReCAAP—in part, some whisper, because of squabbles over where to site its headquarters, but perhaps also for fear of exposing blind spots in their intelligence-gathering.

Indonesia is particularly recalcitrant. It is much poorer than its neighbours on a per-head basis, and its patrol boats are old and costly to run. A plethora of poorly-policed Indonesian islands make for convenient pirate hideouts; the country’s ill-guarded ports allow for many opportunistic thefts. And it probably attaches lower priority to the security of local shipping lanes, reckons Ian Storey at ISEAS, a think-tank, because the benefits of these lanes accrue disproportionately to big ports in Singapore and Malaysia.

Yet some responsibility for solving the problem must also fall on shipowners and operators. Somali pirates were deterred when shippers spent a bit of money to equip their ships with water cannon, razor wire and armed guards. South-East Asian pirates will typically flee if vigilant crews spot them before they board. Shipping companies are often reluctant to report attacks, to avoid alarming their clients and insurers. More alarming is speculation that ill-paid crew members have been complicit in some of the hijackings.

The most durable solution, and the least discussed, would be to target the tricky social and economic problems that encourage pirates to take up cutlasses in the first place. In the past that has meant resolving irksome conflicts. A peace accord between the Indonesian government and rebels in the north-western province of Aceh in 2005 helped to soothe South-East Asia’s previous pirate problems. Many of today’s pirates are thought to come from shabby Indonesian port towns, where overfishing, illegal fishing and environmental damage have made it more difficult to earn an honest living. Pirates who were active a few years ago are thought to be returning to the trade, embittered by the failure of their efforts to go straight.

Joko Widodo, Indonesia’s president, has promised to reinvigorate Indonesia’s flagging maritime economy. That is a good idea, though progress will doubtless be slow. In the meantime, the speedy arrest of pirates in some recent high-profile cases should deter hijackers emboldened by early successes, thinks Pottengal Mukundan of the International Maritime Bureau, a wing of the International Chamber of Commerce. Those in cuffs include the alleged hijackers of the Orkim Harmony, who were picked up by Vietnamese coastguards on June 19th after trying to pass themselves off as survivors of a shipwreck. But Intertanko’s Mr Belcher says shipowners remain largely pessimistic. “It will get worse before it gets better,” he says.