The Libyan eastern-based government said on Monday that all oilfields are closing down, halting production and exports, but the country's Tripoli-based National Oil Corp, which controls oil resources, has not provided confirmation.
Libyan factions are locked in a power struggle over control of the central bank and oil revenues.
The government in Benghazi is not internationally recognised, but most oilfields are under the control of eastern Libyan military leader Khalifa Haftar.
Libya, a major oil producer on the Mediterranean, has had little stability since a 2011 NATO-backed uprising. The country split in 2014 between warring eastern and western factions, eventually drawing in Russian and Turkish backing.
The central bank is the only internationally recognised depository for Libyan oil revenues, which provide vital economic income for a country torn by years of fighting.
The eastern-based government did not specify for how long the oilfields could be closed.
Eastern Libya, where the parliament sits, is controlled by commander Haftar's Libyan National Army (LNA), while the Tripoli-based government, which is internationally recognised, is led by Prime Minister Abdulhamid Dbeibeh.
The NOC has declared force majeure earlier in August in one of the country's largest oilfields, Sharara, located in Libya's southwest with the capacity of 300,000 barrels per day, due to protests in the area.
