Seychelles has sentenced 11 Somali pirates to a decade in prison for attempting to hijack a coast guard in December last year, a regional maritime official confirmed on Tuesday.

Andrew Mwangura, the East Africa Coordinator of Seafarers Assistance Program (SAP) said the ruling by the Supreme Court in Victoria, the first of its kind in the Indian Ocean archipelago, was delivered on Monday.

Mwangura said the 11 pirates were arrested inside Seychelles' territorial waters when they attacked a coast guard vessel with automatic weapons last December.

"Eleven pirates were sentenced to serve a 10 (years) jail term in Seychelles on Monday. The pirates attacked a Seychellois coastguard patrol boat, Topaz in December last year," Mwangura told Xinhua by telephone early Tuesday.

According to a statement issued by Seychelles Department of Legal Affairs, eight of the pirates sentenced were convicted of piracy, and three others of aiding and abetting piracy, for trying to hijack the Topaz patrol boat. Four of them were less than 18 years old.

"Their conviction is a historical milestone as it is the first time that a piracy trial is successfully prosecuted in the Seychelles," said the statement.

Pirate groups have ventured farther out into the Indian Ocean to avoid international warships patrolling Somalia's coastal waters, bringing them into the domain of Seychelles.

"These convictions will serve as a deterrent for prospective Somali pirates who would otherwise have thought they would have come into Seychelles waters with impunity," the Department of Legal Affairs said.

It is only Kenya and the Seychelles in the region that have agreed to take in suspects for prosecution, but both have recently complained about the burden of trying and jailing pirates in their countries.

Early this year, Nairobi formally announced it wished to stop the prosecution of suspected Somali pirates and cancel the agreements it has to that effect with several countries from Asia and Europe.

The foreign ministry had sent "cancellation notes" to at least two of those powers' diplomatic representations in Nairobi, arguing it could no longer bear the burden on its prison and court systems.

The minister accused the international community of failing to keep up its obligations in sharing the burden in prosecuting and imprisoning the detained pirates.

The minister said due to limited capacity of Kenyan courts and prisons as well as financial costs and security concerns, the country can only accept pirates for trial on a case-by-case basis.

However, the threat was later lifted following a meeting between Kenya and the European Union (EU).

Kenya has memoranda of understanding with EU, United States, Canada, Denmark, China and Britain whereby it takes in suspects intercepted at sea and prosecutes them in courts in Mombasa.

The agreements allowing foreign naval powers to hand over suspects to Kenya instead of taking them back home for prosecution.

Kenya shares its southern border with Somalia, whose coastline has been infected with piracy in recent years. More than 160 pirate attacks were reported in the waters off Somalia from the beginning of last year.

Pirate attacks off the Somali coast have continued despite the presence of warships deployed by navies of various countries and organizations including NATO, EU, Russia, China, South Korea and India, in the region to protect cargo and cruise ships against piracy.