Libya’s National Oil Corporation (NOC) has suffered a serious blow in restarting the country’s largest field after an armed group stormed the facilities on Tuesday.

NOC declared force majeure on exports from the Sharara field just days after it was put on line following a blockade that had lasted months.

The armed group, led by Mohamed Khalifa, forced employees at gunpoint to shut down the field which has a capacity of 300,000 barrels per day when fully operational.