Nigerian authorities say kidnappers have released a Polish oil worker seized last week in the country's restive Niger Delta region.
The officials say the Polish national was released late Sunday. He was seized Thursday by six gunmen near the southern city of Warri.
Abduction for ransom or to press political demands is frequent in the oil-rich Niger Delta. In all, more than 100 foreign oil workers have been kidnapped in the region this year. Most have been released unharmed, often after a payment of ransom.
Some kidnappings have been carried out by criminal gangs, while others are the work of militants who want impoverished local villages to get more of the region's oil wealth.
The attacks on the oil industry have caused Nigeria to cut oil production by almost 25 percent.
Some information for this report was provided by AP and Reuters.