BENGHAZI, Libya (AP) — Unidentified assailants abducted workers at a facility belonging to Libya's largest oil field, hampering daily production there, Libya's national oil company said Saturday.

The assailants kidnapped four staff members working at Station 186 of the Sharara field, the National Oil Corporation said in a statement Saturday. It added that only two have since been released. The statement didn't specify if foreign workers were among those abducted.

The Sharara oil field is operated by the NOC in partnership with a consortium that includes Total, Repsol, Statoil, and OMV.

Oil wells nearby have been shut down and workers evacuated as a precautionary measure, the NOC said. It estimates losses to daily production will be around 160,000 barrels per day. It added that it was in touch with authorities and closely monitoring developments.

Libya has descended into chaos following a 2011 uprising that toppled and later killed a longtime ruler Moammer Gadhafi.