He said one of the abductees was Indian, but he had no details on the nationalities of the other men working for a Nigerian oil-services company.
Five gunmen on Thursday grabbed a Polish worker heading to his construction project in southern Nigeria and rushed the captive into the lawless oil-rich region's swamps and creeks in a speedboat, officials said.
Security forces were trying to make contact with the hostage takers, who grabbed the man on his way to work in the southern city of Warri yesterday, said Brig Gen Lawrence Ngubane, a military commander in the region.
The kidnappings are the latest in a run of more than 100 seizures of foreign workers this year in the oil-producing Niger Delta, where all of the crude is pumped in Africa's largest producer.
Some 200 foreign workers have been taken since militants stepped up their attacks against the oil companies and government in late 2005, cutting nearly one third of Nigeria's daily crude production capacity and sending oil prices toward historic highs in oversees markets.