Libya's National Oil Corporation (NOC) has shut down crude production at the Sharara oil field after a kidnapping.
The company said four employees were seized by unknown armed assailants on Saturday at station 186.
Two were later released, but the others remain captive.
The facility is run by Akakus, a joint between NOC, Total, Repsol, Statoil and OMV.
"Oil wells in the surrounding area have been shut down as a precaution, and all other workers evacuated," NOC said.
"Expected losses to daily production are 160,000 barrels a day."
NOC also revealed it had lifted a force majeure declared at the El-Feel field on 23 February.
A dispute caused by the local Petroleum Facilities Guards’ (PFG) demands regarding pay and benefits has been brought to an end, and pumping at the field is expected to resume to 50,000 bpd within two days, and to 72,000 bpd three days later.
The field, located in the Murzuq basin, is operated by Mellitah Oil and Gas Company, a joint venture between Italy’s Eni and NOC.
Negotiations succeeded in guaranteeing an unconditional return of the Fezzan branch of the PFG to their previous locations, NOC said.
Mustafa Sanalla, its chairman, added: "We are happy to announce the return to production at El-Feel. Bringing El-Feel back online will help us swiftly return to maximum production levels”.
