The rival political authorities in Libya are fighting over control of the country's vast oil wealth, Africa's most abundant reserves.
Here are some facts about Libya's petroleum sector:
- The 'oil crescent' -
The so-called "oil crescent" is a region of northeastern Libya, the very heart of the country's economy which is heavily dependent on petro-dollars.
It's the home of the Sirte basin where 80 percent of Libya's oil reserves are found. It's also the zone where four oil terminals are located, in addition to the Hariga port at Tobruk, near the border with Egypt, from where the oil is exported.
The fight for control of this oil crescent has pitted the UN-backed Government of National Accord (GNA) based in Tripoli against a parallel administration based in eastern Libya and backed by the self-styled Libyan National Army, a paramilitary force led by strongman Khalifa Haftar.
- Uneven production, abundant reserves -
Libya produced 1.6 million barrels of oil per day before the ouster of longtime dictator Moamar Kadhafi in February 2011.
Afterwards production fell by about 20 percent before recovering to one million barrels per day by the end of 2017.
But production has again fallen by 450,000 barrels per day after the suspension of operations by the Libyan state's National Oil Corporation (NOC) on June 14 due to violence in the oil crescent.
OPEC has estimated Libya's oil reserves at 48 billion barrels, which makes them the biggest in Africa.
- Foreign companies -
Petroleum production in Libya is shared between NOC and foreign companies which link up with the state-owned corporation.
Italy's energy group ENI is the biggest foreign company in Libya, a former Italian colony, operating there since 1959. Last year ENI said its production rose to the equivalent of 384,000 barrels per day, its highest level in the North African country.
French oil giant Total has also been in Libya since the 1950s. Its production reached the equivalent of 31,000 barrels per day last year, double the level of prior years.
Last spring Total took a share in Libya's Waha oil field, where US oil company ConocoPhilips holds a 16.33 percent stake. The state's NOC retains majority control.
Other groups active in Libya include Spain's Repsol, whose average production was the equivalent of 25,400 barrels per day in 2017, while Austria's OMV was at an average 25,000 bpd in the same period and said it could climb to 40,000 bpd if the political situation improves.
Norway's Equinor -- formerly Statoil -- also has a presence in Libya.
Russian oil giant Rosneft signed a cooperation agreement with Libyan state operator NOC in 2017 with a view towards investing in the country's hydrocarbons.
Map of Libya showing oil and gas fields, pipelines and oil refineries