Spanish energy company Cepsa says it has evacuated an unspecified number of workers from two oil facilities it operates in Algeria following the taking of hostages by Islamist militants at a gas plant in the same region.

A company spokesman said the workers were moved to an area in the center of the country and that the measure was purely precautionary. It said its operations in Algeria were functioning as normal.

Cepsa, owned by International Petroleum Investment Company, says roughly half its production comes from Algeria.

Another Spanish energy company, Repsol, said it was operating as normal in Algeria, where it has less than 10 workers.

Spain receives just under half its gas supplies from Algeria.