Andrew Mwangura of the Kenyan-based East African Seafarers Assistance Programme said the pirates had seized the Thai-flagged ship early on Saturday while sailing from the United Arab Emirates.

"Reports reaching Mombasa ... indicate that early this morning pirates sized MV Thor Nexus some 350 nautical miles east of Salalah, Oman," Mwangura said in a statement.

Mwangura added that it was likely the pirates were Somalis. "They are the ones known to do this," he told Reuters by phone.

The European Union Naval Force (EU Navfor) said in a statement the general cargo ship has a weight of 20,377 tonnes, and put the area of the hijacking at 450 nautical miles north east of Socotra island in the Indian Ocean.

Reuters