Last contact with the Yemeni Navy was late last month . Dozens of ships have been seized by pirates in the Gulf of Aden . Report : No ransom figure yet for hijacked Saudi ships . pirates seized the Blue Star on November 15 .
Last contact with the Yemeni freighter was late last week . Dozens of ships have been attacked by pirates in the Gulf of Aden . Report : No ransom figure yet for hijacked Saudi supertanker . Pirates seized the Sirius Star on November 15 .