Yesterday's ruling came the same day as the French navy transferred 11 suspected Somali pirates to the Kenyan authorities in the port of Mombasa.

The Nivose, a French frigate serving in the European Union's anti-piracy naval mission Atalanta, docked in Mombasa early yesterday, a week after capturing the suspects during a chase in the Indian Ocean.

France's Foreign Minister Bernard Kouchner urged other European countries last night to join French troops in training Somali security forces to fight piracy and terrorism.

France will offer at an international conference today on Somalia to use its troops stationed in Djibouti to train Somali forces.

Earlier in New York, accused pirate Abduhl Wali-i-Musi, wearing a blue T-shirt and with his head lowered as he entered Federal Court with an interpreter, faced a mandatory sentence of life in prison if convicted on the most serious charge of piracy, prosecutors said.

Judge Andrew Peck ruled the young Somali would be tried as an adult after rejecting a claim by the defendant's father that Muse was only 15 years old.

Prosecutors said he was over 18.

''Mr Muse's father's testimony was not credible,'' Judge Peck said.

''The court ruled that the defendant must be treated as an adult.'' The five charges filed against Muse were piracy ''under the law of nations,'' conspiracy to seize a ship by force, conspiracy to take hostages, and discharging and brandishing a firearm in the course of a hostage-taking.

Prosecutor Lev Dassin said, ''An act of piracy against one nation is a crime against all nations. Pirates target ships and cargo, but threaten international commerce and human life.

''Today's charges demonstrate our commitment to hold pirates accountable for their crimes.'' Muse could well spend the rest of his life behind bars unless acquitted.

The piracy charge alone carries a mandatory life sentence, while three other charges carry maximum sentences of life in prison.

Prosecutors allege Muse was one of four Somali pirates who boarded the United States container ship Maersk Alabama on April 8, and later fled taking its American captain, Richard Phillips, as a hostage in a lifeboat. AFP/ AP