Royal Dutch Shell has suspended 455, 000 barrels per day (bpd) of production in southern Nigeria, or 18 percent the country's total output, following the latest attacks on oil facilities, a company spokesman said on Tuesday.

"Shell currently shuts in a total of 455,000 barrels of oil per day, made up of 340,000 bpd from our western operations (in the troubled Niger Delta region), and 115,000 (bpd) from the EA field, " the spokesman told Xinhua.

World attention shifted to Nigeria as oil prices surged as a result of weekend's hostage-takings and attacks on oil facilities by militants in the Niger Delta, where the majority of Nigeria's daily output of 2.5 million barrels is produced.

Currently, there was no clue on the whereabouts of the nine oil hostages, who are employees of U.S. oil services company Willbros, a subcontractor of Shell.

The hostages, three Americans, a Briton, two Egyptians, two Thais and one Filipino, were seized on Saturday morning by the militants from a pipelaying vessel anchored in the Forcados channel in the Niger Delta.

The spokesman said Shell was "taking necessary measures to ensure the safety and security of its workers, contractors and the people in the communities where it operates" and had "evacuated some staff from areas that we consider unsafe."

Willbros said in a statement all its remaining employees in the pipelaying vessel had safely returned to the company's base of operations in the southern Nigerian oil city of Port Harcourt.

"The safety and well-being of our employees is paramount, and since the occurrence of this incident, we are taking all the necessary steps to provide additional security and to assure the safe return of our employees," said Michael Curran, chairman and chief executive officer of Willbros.

Source: Xinhua