Nigeria's main militant group said on Tuesday it was responsible for an attack on an Afren oil rig late on Sunday and that it was holding the crew members kidnapped from the facility.
Gunmen attacked the Afren oil rig in the shallow-water Okoro oilfield off the Niger Delta and seized seven crew members including a Canadian, two Frenchmen, two Indonesians and two U.S. citizens.
"All the abducted expatriates are well and in our safe custody," the Movement for the Emancipation of the Niger Delta (MEND) said in an e-mailed statement.
It said it would soon release the names of all foreigners being held in its camps.
The group said on Monday it was also holding one Thai and three French nationals who were kidnapped several weeks ago and had since been transferred to its custody.
The three Frenchmen were kidnapped from a vessel owned by French marine services company Bourbon on Sept. 22 by gunmen in speedboats.