Nigerian police say armed men wearing camouflage uniforms have kidnapped a German oil industry worker in the country's Niger Delta region.

A police spokesman says the kidnappers took the worker from his car near the southern city of Port Harcourt Thursday.  The German man works for the company Bilfinger Berger. 

Police have not named any suspects in the case.

Kidnappings are common in the delta region. Local militants want residents to receive more of the region's oil revenues.

On Monday, Nigerian militants released eight soldiers and 16 oil workers they had held hostage at an oil pumping station for a week.

Nigeria normally produces about 2.5 million barrels of oil per day.  But recent attacks on oil facilities and the kidnappings have slashed production by at least 20 percent since February.