sources@ (Adds details on El Feel)
TRIPOLI, Aug 27 (Reuters) - A local Libyan brigade has closed down two valves on a pipeline to Sharara oilfield, the country's largest, to make demands for more fuel supplies and better economic conditions for the Zintan region, a source in Zintan said on Sunday.
Another field, El Feel, has also been shut because of the pipeline blockade, and state-run National Oil Corp (NOC) has declared force majeure on Mellitah crude exports due to the closure, two Libyan oil sources said on Sunday.
Sharara, which was producing around 280,000 barrels per day, had been shut down a week ago, engineers said, and NOC declared force majeure on loadings of Sharara crude from the Zawiya oil terminal, according to a company document.
Another brigade tasked with oil facilities protection has closed a pipeline leading to the Hamada field, but the field was still operating and talks on reopening the pipeline were expected on Sunday, a spokesman for state company AGOCO said.
Six years after the fall of Muammar Gaddafi, Libya is caught in a power struggle among competing factions and various armed brigades, with a U.N.-backed government unable to impose control.
The OPEC country's oil infrastructure is often the target of blockades and protests, although production has recently risen closer to the 1.6 million barrels per day the North African state produced before the 2011 revolt against Gaddafi. (Reporting by Ahmad Ghaddar in London; Ahmed Elumami in Tripoli and Ayman Al-Warfalli in Benghazi; writing by Patrick Markey and Louise Heavens)