No one claimed responsibility for the kidnapping immediately, The Times of London reported. It was believed to be the work of one of the militant groups that hold foreign oil company employees for ransom, the report said.
All four kidnap victims are employees of Netco Dietsmann, a joint venture of the state-owned National Engineering and Technical Company and Dietsmann, a Dutch maintenance company. The company identified them as John Bennet, Kevin Gray, Martin Phillips and Fabien Sanchez.
The men were traveling in a bus with security guards to Afam, a gas and power plant operated by Shell east of Port Harcourt, when they were attacked at about 7:30 a.m.
There has been less violence in the Delta since a government amnesty last year that allowed militant groups to surrender their weapons. But a Chevron pipeline was sabotaged Friday.