Four South Korean workers and a Nigerian have been abducted by an unidentified armed group at a Korean company\'s construction site in southern Nigeria, Yonhap news agency quoted Seoul\'s foreign ministry officials as saying Tuesday. The armed group broke into the construction site at Brass Island in the state of Bayelsa and drove the five abductees away in a boat from the site at around 3:00 p.m. on Monday (local time), ministry officials said. The armed group had originally kidnapped the four Koreans of Hyundai Heavy Industries and two Nigerian colleagues, but one Nigerian was ordered to get off the boat and returned to the construction site, said a senior ministry official. \"No contact has been made yet from the kidnappers, and we are closely cooperating with local police for their safe release,\" the official said on the condition of anonymity.