( CNN ) -- Pirates off Somalia have hijacked two more vessels in the Gulf of Aden , the European Union naval force said Saturday -- the third and fourth vessels they have captured this week . The British-flagged Asian Glory was seized off Somalia late Friday , the naval force said . The nationality of the pirates was unclear , because the hijacking happened outside of the force 's operations area , it said . The British Foreign Office would not confirm the hijacking , but said no British nationals were aboard . Also Friday , Somali pirates seized the Singaporean-flagged chemical tanker M/V Pramoni , also in the Gulf of Aden , the naval force said . The 20,000-ton chemical tanker was carrying a crew of 24 and was heading to Kandla , India , when attacked , the naval force said . The crew consists of 17 Indonesians , five Chinese , one Nigerian and one Vietnamese , the naval force said . The ship 's master reported all the crew were well after the hijacking , the naval force said . The ship was heading toward Somalia after the hijacking , the naval force said . The Asian Glory is owned by London-based Zodiac Maritime Agencies , according to Lloyd 's Register of Ships . Zodiac also owns another vessel that was hijacked in the Gulf of Aden , the British-flagged chemical tanker St. James Park , according to the company 's Web site . The St. James Park has a crew of 26 , consisting of Bulgarians , Filipinos , Georgians , Indians , Poles , Romanians , Russians , Turks and Ukrainians , the EU naval force said . The vessel had arrived at the Somali port of Hobyo , a pirate stronghold , the naval force said Saturday . Monday , pirates also hijacked the Greek-owned carrier Navios Apollon , the naval force said . It had been heading for Thailand , but was on its way to the Somali coast after the hijacking , it said . CNN 's Per Nyberg in London , England , contributed to this report .
Thailand Foreign Office : No British nationals aboard British -flagged Asian Glory . Singaporean pirates seized Singaporean -flagged chemical tanker Navios Apollon Friday . one other vessels -- Two British -flagged , the other Greek -owned -- taken in past week .