Libyan oil-facility guards prevented two of the country’s biggest fields from resuming production, days after the National Oil Corporation (NOC) reached an agreement to restart operations there to boost output, Bloomberg reported.

The El Feel, or Elephant, and Sharara fields still aren’t operational after they were shut more than 18 months. An engineer at Mellitah Oil & Gas, Khaled Hadloul, said that a group of guards backtracked on their agreement to let oil flow by pipeline from both fields. He added: “It’s not clear when the actual output will start. Negotiations with the guards are ongoing,” informed World Oil.

Repsol SA-operated Sharara, Libya’s largest field, also has yet to restart because both fields in western Libya feed into the same pipeline network. Eni SpA has a stake in Elephant.

The inability of either field to reopen is a setback for the state-run NO), which reached an agreement with protesters who had been blocking pipelines that connect the deposits with the Zawiya refinery and Mellitah complex. The deal spurred hopes for an increase in production from the North African country, following years of turmoil and conflict among militia groups for control of its energy facilities.

This comes as the oil port of Es Sider shipped 80,000 tons of crude in late December. The overseas cargo was the first to sail from the country’s biggest export terminal in two years.