A foreign worker has been taken hostage by gunmen in Nigeria's troubled oil-region. This is the first kidnapping of a foreign national for almost five months and it has raised fears that a period of relative calm in the Niger Delta could be coming to an end. For VOA, Sarah Simpson has more from Lagos.

Gunmen kidnapped a foreign construction worker near the city of Port Harcourt in the oil-rich Niger Delta Tuesday. The assailants killed at least one soldier who was escorting the worker, according to private security officials speaking on anonymity.

The German-Nigerian construction company Julius Berger confirmed to VOA that the hostage was an employee, but it refused to provide the person's nationality or any further details.

This is the first recorded hostage-taking of a foreign national in the troubled region since October, though hostage-taking of Nigerians has remained a persistent problem.

Last year, more than 150 foreign nationals were abducted for ransom by criminal gangs operating in the oil-rich south.

Incidents fell after thousands of foreign workers and their families were evacuated or relocated from the oil-producing region.  Security for those who remained was tightened.

Fresh peace talks between the government of new President Umaru Yar'Adua, inaugurated in May, and militant groups operating in the Delta also contributed to the relative calm.

But the main militant group, the Movement for the Emancipation of the Niger Delta (MEND) has threatened a return to violence after one of its leaders was extradited to Nigeria by Angola, where he had been detained on gun-running charges.

MEND attacks on oil installations, including the blowing up of pipelines and kidnapping of foreigners, slashed Nigeria's crude production by about 20 percent and forced up oil prices worldwide.

MEND says it is fighting so a greater share of the national oil wealth is distributed to the Niger Delta.

But analysts say the violence has spiraled out of control and hostage taking has become a lucrative criminal enterprise in a region awash with guns and beset by poverty.