The crew of a Taiwanese fishing vessel have overwhelmed a group of Somali pirates who hijacked their boat last week.The 28-member crew of the Chin Yi Wen were taken hostage while sailing off the East African coast and disappeared from radio contact on 4 November.The six pirates were later attacked and overwhelmed by the sailors.Several hundred people and dozens of vessels are currently held captive by Somali gunmen.The Chin Yi Wen disappeared from radio contact while several hundred kilometres off the coast of Somalia last week.A group of armed pirates initally took control of the boat, but were defeated when the crew fought back. According to Taiwan's Fisheries Agency, three sailors were injured, while the pirates fell into the sea. Their fate is not known.The fishing crew later sought the assistance of the United Kingdom Maritime Trade Operations (UKMTO), an international anti-piracy task force which patrols the area under the supervision of the UK.The International Maritime Bureau has said that better policing and improved security have reduced successful hijackings by Somali pirates this year.A US study found that maritime piracy costs the global economy between $7bn (£4.4bn) and $12bn (£7.6bn) a year.