Somali pirates have freed a Nigerian tugboat captured around 10 months ago, putting an end to the longest such hijacking off the coast of Somalia, a maritime watchdog said on Saturday.
"Yenegoa Ocean is free," said Andrew Mwangura, who heads the Nairobi-based East African Seafarers Assistance Programme.
The ship -- owned by Nigerian ESL Integrated Services -- and its 10-man crew were captured in the Gulf of Aden on August 4, 2008.
According to a Dutch navy statement, the tugboat was freed at 1800 GMT on Friday and is being escorted by a Dutch frigate.
At last 14 ships are still being held by Somali pirates in the Gulf of Aden and Indian Ocean, together with more than 200 seamen, almost a fourth of them Filipinos.
According to Ecoterra International, an environmentalist NGO monitoring illegal marine activities in the region, Somali pirates have carried out 126 attacks in 2009, including 44 successful sea-jackings.
They had captured 49 ships in the whole of 2008.
Early April this year saw an unprecedented flurry of hijackings but less favourable weather conditions in recent weeks have led to a relative lull in pirate attacks.