A police spokesman in Nigeria says Hyundai Heavy Industries Co. paid about $187,000 to kidnappers to free four abducted South Korean workers and their Nigerian colleague.

Bayelsa state police spokesman Fidelis Odunna told The Associated Press on Friday that one of the kidnappers said ransom was paid. Odunna said such payments to kidnappers will embolden others to carry out similar attacks on foreign workers.

The workers were kidnapped Dec. 17 at a construction site in Nigeria's oil-rich southern delta. South Korea's Foreign Ministry announced Dec. 22 that the men had been freed.

Kidnappings for ransom are frequent in Nigeria's Niger Delta. Experts say kidnappers who once targeted mainly expatriate oil workers have recently shifted their focus to wealthy Nigerian families.