The international community should act now and "not 20 years from now" to end the spiralling problem of piracy at sea, especially off Somalia, an international conference in Stockholm said on Wednesday.

In a draft declaration, the three-day International Conference on Piracy at Sea (ICOPAS) described the the humanitarian and economic costs of piracy as "unacceptable".

"Political will, effort (and) coordination are needed to address the root causes and to deter and defeat piracy," said the declaration, calling on the United Nations to create a "Maritime Enforcement Mandate" within Somalia's economic zone to protect Somali and international interests.

"The reality is that a few hundred (people)... are being held against their will in Somalia and a few other parts of the world," said conference chairman Maximo Mejia of the World Maritime University

"Something needs to be done about the situation today, not 20 years from now, not 30 years from now," he added, speaking at the close of the three-day conference in the southern town of Malmoe.

This year there have been a record 352 pirate attacks worldwide, according to a report this week by the International Maritime Bureau (IMB).

Somali pirates, who have created an industry based on hijackings and ransom payments in the strategic waters next to their lawless homeland, accounted for 199 of the attacks, up from 126 during the same period last year, according to the report.

"People in the (maritime) industry have been stretched to their limit of patience," Mejia said.

The 410 conference participants from around the world "were not optimistic but still hopeful" that the international community and national governments would do more to end the "scourge", he said.

Among their many recommendations, the participants called on the international community to develop "innovative international tools to overcome the constraints of national boundaries and jurisdiction in dealing with piracy."

They also demanded that national governments "honour their obligations to successfully prosecute and punish pirates."

"There is a whole laundry list of things that need to be done," Mejia said, adding though that perhaps the most important focus should be on putting "Somalia back on its feet".

"You can only eradicate piracy if you get at its roots. What is piracy but a manifestation of the problems they are experiencing on land?"

"If you had pirates here, you'd have police and the navy to combat the threat, but there, there is no navy, there is no police, there is no government. It's a big fat can of worms," he pointed out.

The conference addressed a number of contentious issues, Mejia said, mentioning the use of privately contracted security personnel to help ward off pirate attacks and especially how to handle the fact that many if not most of the pirates who are caught were under the age of 18.

"It is becoming more and more apparent. It's really the rule rather than the exception (that the pirates are under 18) and that has international legal implications.... You can't really prosecute these people as pirates, but more as juvenile offenders," he said.