Piracy on the high seas is a growing problem, made worse by Asia's economic crisis, say delegates attending a three-day seminar organised by the International Maritime Organisation.

They say that pirates are now well-organised, chose their targets carefully and can make millions of dollars from their activities. They are also increasingly violent - last year 67 people died in pirate attacks world-wide, and hundreds were taken hostage.

Pirates target all sorts of craft, including oil-tankers. It is not unknown for commando-style gangs in face-masks to clamber aboard, murder the crew and then siphon hundreds of thousands of litres of oil into another vessel, before smashing up the tanker's navigation system, leaving it to sail on with nobody in command.

23 murdered

One of the most recent attacks involved a bulk carrier sailing in the South China Sea. All 23 crew members were killed and their bodies weighted and thrown overboard. Days later they became snagged in fishermen's nets.

But not all attacks are so carefully pre-planned. The waters off Indonesia, one of the countries worst affected by the regional economic downturn, saw about 30% of the nearly 200 reported attacks last year.

Many of those were attributed to desperate people targetting any vessels that they believed were carrying food.

Ecological disaster feared

The three-day piracy seminar, involving officials from 10 economies, will discuss co-operation agreements between neighbouring countries to combat the problem, as well as look at the legal implications of allowing warships to battle pirates in international or territorial waters.

Many delegates' greatest fear is that a major collision or ecological disaster could result from a pirate attack.