Somali pirates have freed an Italian oil tanker hijacked in February with five Italians and 17 Indians on board after nearly 11 months in captivity, the Italian government said on Wednesday.

Prime Minister Mario Monti "expressed his great satisfaction for the release of the Italian ship Savina Caylyn and the crew," it said in a statement.

The crew and their families had faced "a harsh test" over the past months, it added, without providing details on how the ship came to be released.

The 105,000-ton tanker owned by Naples shipping company Fratelli D'Amato was seized on February 8 after five pirates aboard a skiff opened fire with rocket launchers and submachine guns near the Yemeni island of Socotra.

The ship had tried to evade capture by speeding up, suddenly changing gear and firing powerful water jets on the pirate boat.

The ship was on its way from Sudan to Malaysia and was carrying a load of crude oil for the Arcadia commodities trading company.

The Savina Caylyn was the last Italian ship in Somali pirate hands.

A merchant ship captured in April off the coast of Oman with six Italians and 15 Filipinos on board was released in November after a ransom was reportedly paid, dropped off from a small plane into pirate hands.

In October, British and US commandos raided a hijacked Italian vessel, capturing the pirates and freeing the carrier's crew of 23 including seven Italians, 10 Ukrainians and six Indians.