Last contact with the Saudi freighter was late last week . only one of ships have been attacked by pirates in Africa . Report : No ransom figure yet for hijacked Saudi supertanker . Pirates seized the Sirius Star on late last week .
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 .