A gang clambered onto the 7,600-dwt SP Brussels (built 2007) in the Niger Delta on Monday before making off with the hostages.
Operator Medallion Marine says it is working with local authorities to ensure the safe return of its employees.
“The remaining crew members are all safe and the vessel has now arrived at the port of Lagos,” a statement said.
While Medallion did not offer any information relating to the hijacked crew, sources have suggested three Indians, a Pakistani and a Ghanaian have been taken.
Confirmation of the incident comes only 24 hours after four Hyundai Heavy Industries employees were snatched from a crewboat off Bayelsa state.