Somali pirates have seized a Taiwanese fishing vessel with 14 crew members on board in the Indian Ocean, near Mauritius, an international maritime organization said on Friday.

The Kenya-based Ecoterra International said that contact was lost with the vessel FV Feng Guo on Oct. 4 and very likely it had already been seized, along with its 14 crew members.

"A ransom is reported to have been demanded for its release, although in the meantime the ship may also be used as a 'mothership' in other sea-jacking attempts," the organization said.

Ecoterra advised crews of other vessels to exercise caution once they spot a white-hulled fishing vessel acting suspiciously in the area.

Andrew Mwangura, East Africa's coordinator of the Seafarers Assistance Program (SAP) also confirmed the hijack, but could not confirm the nationalities of the crew.

"The Taiwanese fishing vessel lost contact on Oct. 4 and it is feared that the vessel has been hijacked," Mwangura told Xinhua by telephone from Mombasa on Friday.

Somalia is at the entrance to the Gulf of Aden, which leads to the Red Sea and the Suez Canal, one of the world's most important shipping channels.

Somalia has been plagued by factional fighting between warlords and has not had a functioning central administration since the 1991 ouster of former dictator Mohammed Siad Barre.

International military officials have vowed to fight Somali pirates who have moved into the waters off the coast of East Africa.

Crews have been successfully repelling more attacks, making it harder for pirates to capture ships and earn multi-million-dollar ransoms. But the pirates responded more violently.

Many shipowners are investing in physical defenses, like stringing razor wire and adding fire hoses that can hit attackers with streams of high-pressure water. Some ships even now have electric fence-style systems installed.