Gunman have kidnapped three oil workers from Canada, Scotland and Nigeria at a rig in the Delta region of the country on Saturday.
The Nigerian military officials on Sunday confirmed what is the second abduction in the area in less than a week.
On Thursday last week, two Royal Dutch Shell oil workers were kidnapped and their police escorts killed in Rivers State while returning from a trip.
The military Spokesperson for Operation Delta Safe, Major Ibrahim Abubakar, said the attackers raided the rig owned by Niger Delta Petroleum Resources in Ogbele, Rivers State at around 8 a.m. (0700 GMT),
Abubakar said the troops were searching surrounding swamps, while the State police said they had stepped up security on an east-west road where armed men had attacked civilians in recent weeks.
The Niger Delta produces the bulk of Nigeria’s crude. It has been plagued by criminal gangs and by armed groups demanding a greater share of oil revenues for the region.