Updated

AMSTERDAM-- A Dutch court sent two Somalis to jail for up to seven years on Friday for hijacking a South African yacht last year and seizing a South African couple who are still missing. Three others also were convicted of piracy.

The five men were caught by the Dutch navy in the Gulf of Aden in November, heavily armed with machine guns and bazookas.

Prosecutors failed to prove a link between three of them to the sailboat Choizil, which was seized off Tanzania's coast two weeks before the Somalis were captured. The yacht was run aground and the captain rescued. But a South African man and his wife who were taken hostage remain in pirates' hands with a $10 million ransom demanded for their release.

The sentences handed down by the Rotterdam court ranged from seven to 4 1/2 years imprisonment. As customary in the Dutch judicial process, the names were not publicized even after conviction.

In similar cases this year, a U.S. court in Virginia sentenced five Somalis to life in prison and a Spanish court in Madrid sentenced two convicted pirates to 439 years each.

Prosecution spokesman Wim de Bruin said the sentences were in line with Dutch law which provides a maximum 9-year term for piracy, and 12 years for a pirate captain. The 17th-century law against sea robbery has not been revised since modern pirates began plaguing the sea lanes off Africa's eastern coast.

A court statement said the five men were intercepted at sea by a Dutch naval ship in November before they could seize another ship.

In determining sentence, the judges dismissed arguments that the men were driven to piracy by poverty and famine.

Instead, they took into account the professionalism of the pirates in organizing violent attacks against international shipping.

"The court has emphasized that piracy in the Gulf of Aden has turned into a significant threat for all ships that frequent the region," said the statement. "Global economic consequences can no longer be ruled out."

Two decades of anarchy in Somalia have allowed pirates to flourish off its coasts. For years, complicated legal issues dissuaded countries from prosecuting captured thieves, and most were released or handed over to Somali or Kenyan courts. But the Dutch case reflects a shift by maritime nations to take action themselves.

At least 17 nations around the world have tried or are prosecuting pirates.
The Rotterdam trial was the second by the Netherlands, and other pirates captured by the Dutch navy have been extradited to Germany. The Dutch also are prosecuting another 16 people captured after a gunbattle in April in which two pirates were killed.