Washington  - A suspected pirate in the hijacking earlier this month of a US-flagged ship off the coast of Somalia will be tried as an adult, a federal judge in New York ruled Tuesday, according to broadcaster CNN.

The alleged pirate was taken Monday night to New York by US law enforcement agents to go before a judge about his alleged role in the hijacking of the Maersk Alabama on April 8 in the Indian Ocean.

The Somali suspect's defence attorneys placed his age at 15, based on information provided by his father, while prosecutors believe he is older. A trial as an adult will ensure the proceedings take place in public.

The suspect arrived in New York sporting a wide grin and a hand bandaged after being wounded during the ordeal, which ended last week when Navy special forces killed three pirates holding the captain of the ship as a hostage on a lifeboat.

The defendant and the three slain pirates had sought to take control of the Maersk Alabama, but the ship's crew seized the vessel back from the hijackers. Four of the pirates escaped with Captain Richard Phillips as a captive.

Phillips spent five days on a lifeboat with the pirates as the small vessel was shadowed by the US Navy. Three Navy SEAL snipers aboard the USS Bainbridge fired simultaneous shots to kill the three pirates, freeing Phillips.

The seizure of the Alabama brought heightened US attention to piracy, which has risen dramatically off Somalia's coast in the last year. Pirates take the ships and the crews, hoping to receive hefty ransom from shipping companies.

The fourth pirate, who was onboard the Bainbridge for treatment of a hand injury when the snipers struck, was held by the Navy before being transferred to federal law-enforcement agents. (dpa)