Suspected militants have kidnapped four nationals of United Kingdom  in oil rich Niger Delta. They had been working in the Burutu area of Delta state in the south of the country, a local leader said.

Delta state police spokesperson Andrew Aniamaka told AFP that they had been abducted on Friday.

"The victims are of British nationality, two of whom are a couple, and have been rendering humanitarian services in the area for a while," he said.

"But unfortunately, they didn't let the authorities know of their presence in the area all this while. There is a militant group that has been operating in the area and we believe they are the ones behind the abduction."