Piracy off the coast of Somalia is outpacing efforts to combat it and more is needed to attack the problem at its root by creating economic alternatives for young Somalis, a top U.N. official said Tuesday.

B. Lynn Pascoe, U.N. undersecretary-general for political affairs, said more than 438 crew and passengers and 20 ships are currently being held at sea off Somalia as pirates employ larger vessels and attack further off the coast to avoid stepped up patrols.

"The pirates are taking greater risks and seeking higher ransoms," Pascoe said. "The problems would be worse if not for the very considerable international anti-piracy efforts under way."

The EU, NATO and regional navies are increasingly working together to patrol the Gulf of Aden — one of the world's busiest shipping lanes crossed by about 20,000 vessels annually — and other waters off Somalia where pirates operate.

Secretary-General Ban Ki-moon said in a report that pirates have expanded operations well into the Indian Ocean, up to 1,000 nautical miles from Somalia. Some pirates have even begun using a "mother ship" towing two or three skiffs to help launch attacks far off the coast against ever-larger freighters.

British Ambassador Mark Lyall Grant said Security Council members believe naval operations alone will not resolve the problem.

"It is also important to tackle the root causes," he said, advocating increased security on land and alternative sources of income for Somalis.

Pascoe suggested rehabilitating existing coastal fisheries the construction of new ones as a way to create more jobs for Somalis.

"As long as piracy is lucrative, with ransom payments adding up to tens if not hundreds of millions of dollars, and other economic incentives so bleak, the incentives are obvious," he said.

Somalia, which has been without a functioning government since clan-based warlords topped dictator Mohamed Siad Barre in 1991, has been incapable of tackling the problem on its own.

Complicating matters are issues of jurisdiction over who can try crimes committed in international waters.

Neighboring countries have had only limited success prosecuting pirates, and a new court decision in Kenya could further harm international efforts to halt piracy.

Judge Mohammed Ibrahim of Kenya's second-highest court ruled Tuesday that the country does not have the jurisdiction to try pirates if the attacks occurred outside Kenyan waters and ordered nine Somali men charged in a March 2009 attack on a German cargo ship freed because the attack occurred in the Gulf of Aden. Kenya's Attorney General has filed an appeal.

In the past, Kenya in the past has tried and sentenced 18 pirates in separate cases and is holding another 123 piracy suspects for trial.