Algerian special forces launched a rescue operation yesterday at a natural gas plant in the Sahara Desert and freed foreign hostages held by al Qaeda linked militants, but estimates for the number of dead varied wildly from four to dozens.

British, Spanish and Norwegian oil companies were evacuating workers from Algerian energy facilities today following the hostage-taking by Islamic militants in the Sahara desert and Algeria’s attempt to free them.

The family of an Irishman held in the Algerian hostage crisis have described their delight at his release after two days of anguish.