Somali pirates have released a Yemeni fishing boat they seized earlier this month in the Gulf of Aden, a Kenyan maritime official said.
The MV Fallujah was captured on December 10 alongside another Yemeni fishing vessel MV Kana, which is still in the hands of the hijackers, said Andrew Mwangura who runs the Kenyan branch of the Seafarers Assistance Programme.
"Reports from Yemen indicate the fishermen have already arrived in Aden," Mwangura said, adding that 10 fishermen had been freed along with the boat.
More than 100 attacks have occurred in the pirate-infested waters off the coast of the lawless Horn of Africa country this year alone.
The pirates have been undeterred by the presence of foreign navies patrolling in the Gulf of Aden and the Indian Ocean in a bid to secure one of the world's busiest shipping routes.
Meanwhile, the Yemeni government said it is creating a regional anti-piracy centre to battle the growing number of high-seas hijackings by Somali pirates in the area.
The centre will act as a hub for the exchange of information about piracy and for the co-ordination of multi-national naval forces in international and Somali territorial waters, a Yemeni transport ministry spokesman was quoted as saying by the official Saba news agency.
Yemen has already started work on building the centre, which should be completed in about six months, with 10 Red Sea and Gulf of Aden countries taking part, the official said.
Increasingly emboldened pirates using fleets of small, fast boats have carried out more than 100 attacks in the Gulf of Aden and the Indian Ocean this year.
Last month, they captured world attention when they hijacked the Saudi-owned super-tanker Sirius Star, carrying two million barrels of crude oil, and demanded a $25-million (Dh92m) ransom for the ship and its crew.
It is one of about 17 vessels, including an arms-laden Ukrainian cargo ship, and some 300 sailors currently in pirate hands.
Arab nations on the Red Sea met in Cairo in November and committed to co-operate in the fight against the pirates, but did not announce concrete measures
Over the past year, Somali pirates have hijacked everything from luxury yachts to oil tankers, defying foreign navies and holding the world to ransom over one of the planet's busiest trade routes.
What was once a group of disgruntled fishermen has turned into a fearsome organisation, which has attacked more than 100 ships this year alone and raked in an estimated $120 million in ransom money.
Somali pirates captured the world's attention when they hijacked a Ukrainian cargo carrying combat tanks in September and a Saudi-owned super-tanker laden with two million barrels of crude two months later.
Armed with rifles, grenade-launchers and grapnel hooks, the pirates have wreaked havoc in the Gulf of Aden, where thousands of merchant vessels bottle-neck into the Red Sea each year.
The cost of ransoms, delays and insurance premiums has hit the shipping industry hard, prompting some companies to opt for the longer but safer route around the Cape of Good Hope.
"This unprecedented rise in piracy is threatening the very freedom and safety of maritime trade routes, affecting not only Somalia and the region, but also a large percentage of world trade," the top UN envoy to Somalia, Ahmedou Ould Abdallah, said recently.
The latest high-profile hijackings have jolted the international community into action, with the dispatching of naval forces by the European Union and Nato to bolster already existing operations in the region.
Brussels earlier this month trumpeted its first-ever naval force, dubbed Atalanta, but pirates have demonstrated their ability to adapt to growing surveillance and started shifting their attacks further south and out to sea.
Foreign navies have thwarted some attacks but pirates have hardly been deterred and obstacles remain to finding an approach that would curtail piracy off the Somali coastline.
In its first mission beyond territorial waters, China also sent two destroyers and one supply ship to join the fleet of foreign navies patrolling the pirate-infested waters.
The number of different countries and jurisdictions involved create many legal complications to effective anti-piracy efforts.
For example, if US naval forces board a Greek-owned Panamanian-flagged ship with a Chinese crew to arrest Somali pirates and transfer them to Kenya, no fewer than six nations are involved.
"Piracy poses an enormous challenge to the international legal system," UN humanitarian co-ordinator for Somalia, Mark Bowden, said at an international conference on piracy in Nairobi earlier this month.
Experts have outlined a programme that would allow naval coalition countries to transfer detained pirates for prosecution in coastal countries such as Kenya, Yemen, Djibouti or Tanzania.