Four foreign oil workers held hostage in southern Nigeria for more than two weeks have been released, an official for Royal Dutch Shell said on Monday.

"I can confirm they have just been saved," said the official who asked not to be named.

A government spokesman for the southern state of Bayelsa said the four were now in good condition.

A local journalist in Yenagoa, the state capital, told Xinhua that they are waiting to see the four men who were abducted from a Shell offshore oil field on January 11.

The four, an American, a Briton, a Bulgarian and a Honduran, were staff of Shell's two subcontractors, Tidex and Ecodrill.

Nigeria's ThisDay newspaper quoted security sources as saying that the Bayelsa state government whose negotiators secured the release may have to meet "monetary conditions" which were not specified.

The hostage-takers, however, in an email to the media stated that they agreed to release the hostages "purely on humanitarian grounds" and that no request was made for money.

Meanwhile, they claimed that the release did not signify a ceasefire and the attack on oil facilities would continue.

Nigeria is the biggest oil producer in Africa with a daily output of 2.5 million barrels of crude oil, while Shell accounts for half of the country's oil production, but the situation in the country's oil-producing Niger Delta in the south is turbulent.

Villagers there accuse oil firms of not doing anything to develop the impoverished area. As a result, they frequently shut off oil wells, kidnap oil workers or commit other forms of violence to blackmail companies operating in the oil fields.

Source: Xinhua