21 December 2012 Last updated at 23:11 ET

Nigeria gunmen free South Korean Hyundai workers

Four South Korean workers for Hyundai have been freed days after being snatched by gunmen in Nigeria.

Gunmen kidnapped the Koreans, along with two Nigerians, in the oil-rich Bayelsa state on Monday.

Officials in Seoul said in a statement that the four Koreans had been freed, but gave no details of the fate of the Nigerian workers.

Kidnappings of foreigners for ransom are common in the Niger Delta, Africa's main oil region.

South Korea's Foreign Ministry said the four workers were released after "persistent persuasion."

Nigeria is one of the worst countries in the world for kidnapping, where it is a lucrative criminal enterprise worth millions of dollars a year.

Oil workers and other foreign nationals working in the southern region are often targeted because companies will pay high ransom money to secure their employees' release.

Earlier this month, the mother of Nigeria's Finance Minister Ngozi Okonjo-Iweala was snatched from her home in the Delta state.

Kamene Okonjo was freed on Friday after gunmen held her for five days.

The minister said the kidnappers had demanded her resignation.