Pirates have stepped up their attacks on vessels off the coast of Somalia.

The internationally recognized definition of piracy is found in the U.N. Convention on the Law of the Sea.

"Article 101 of the (U.N.) Convention on the Law of the Sea defines piracy as illegal violence or detention, depredation by the crew or passengers of a private ship or aircraft against other such ship or aircraft on the high seas or outside the jurisdiction of a state," said J. Peter Pham, a maritime security expert with James Madison University in Harrisonburg, Virginia.

According to the London-based International Maritime Bureau, an organization that tracks crimes on the high seas, the waters off Somalia, including the Gulf of Aden, are the most dangerous in the world for international shipping.

The International Maritime Bureau says last year was the most successful ever for the pirates. Based on figures for the first three months of this year 2009 will be even better for them - 61 ships were attacked in that region as compared to six in the first quarter of 2008.

In an effort to combat piracy off the coast of Somalia, in the past few years, the international community has deployed navy ships to patrol the area. The task force includes vessels from the United States and the European Union. Russia, China and India have also ships in the area.

Analysts such as Roger Middleton, with the London-based Chatham House, say complications arise when the pirates are captured.

"In most cases, to be honest, when pirates are picked up by navies, their guns are taken away, their boats may be taken away and then generally, they are released. Because the legal situation is a little bit unclear about when is it possible to prosecute the pirates, and how effectively that will happen. The real worry is that you capture some pirates, you send them back to Paris, for example, the case is thrown out of court and then the pirates have a free ride to Europe," he said.

RAND Corporation maritime expert Peter Chalk says letting pirates go poses difficulties. "If you return them to Somalia, for instance, on the one hand you could be essentially just freeing them because if they are returned to coastal communities, those communities have a vested interest in these people and they protect them. But if you also return them to areas, say, where Islamist entities are in power, the chances are they will be executed and so that raises human-rights concerns. So they will probably be set adrift in a boat close to the shoreline - and then they go wherever they want after that," he said.

Chalk and others say the main reasons pirates are let go are that many countries are either unwilling to prosecute them or do not have specific national legislation penalizing piracy.

In an effort to remedy that, analysts say a number of countries such as the United States and members of the European Union have signed an agreement with Kenya, the closest country to Somalia that has a judiciary capable of prosecuting pirates.

Pham says the Kenyan parliament in February passed a new merchant shipping law updating the country's statutes under which pirates can be prosecuted.

"However that law, although passed by parliament, has yet to be signed by President Mwai Kibaki who, for reasons of internal domestic politics has left the bill sit on his desk unsigned. So as a result, Kenya certainly has agreements with the United States, the European Union and other parties to try such people as they might drop off. It is trying them under a relatively antiquated statute and so Kenya really needs to move and enact the updated statute," he said.

Middleton says on paper, Kenya has all the tools to deal with pirates. "But it does lack something in capacity - there are about three judges in Kenya who are qualified to hear these cases. The Kenyan legal system is already very stretched in terms of space in court, lawyers and also space in prisons. So there are some really serious capacity constraints for Kenya to deal with these," he said.