(Xinhua) -- Armed Somali pirates have hijacked a chemical tanker with 28 North Koreans onboard in the latest attacks along the world's most dangerous waters, a regional maritime official said on Tuesday.

Andrew Mwangura, the coordinator of the East Africa Seafarers Assistance Program (SAP), said Kiribati flagged-MV Theresa VIII was seized on Monday 618 nautical miles North West of the Seychelles on its way to the Kenyan port of Mombasa.

“She was taken on Monday at 1053 hrs some 618 nautical miles north west of Seychelles. All 28 crew members on board are North Korean nationals. The vessel is Bulgarian owned,” Mwangura told Xinhua by telephone.

He said the Singaporean-operated chemical tanker was seized in the south of the Horn of African nation which has been without an effective central government for more than two decades.

Marshall Islands-registered Filitsa was captured last Wednesday, about 513 miles off north of Seychelles with three Greeks and 19 Filipinos on board.

The Filitsa vessel on its way to Somalia where pirates have increasingly been using highly sophisticated equipments to step up attacks on merchant vessels in the Gulf of Aden, increasing insurance costs for ship owners and raising the possibility of military intervention.

The Horn of Africa nation's coastline is considered one of the world's most dangerous stretches of water because of piracy.

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.

The country has been plagued by factional fighting between warlords and hasn't had a functioning central administration since the 1991 ouster of former strongman Mohammed Siad Barre.