Southern Libya could be thrown into even greater turmoil in the coming weeks, as militias allied to the Libyan National Army (LNA) begin pushing into the restive southern Fezzan region in an effort to improve security and secure some of the country’s most important oil fields.

“We have started a full-scale military operation in the southwest of Libya,” a spokesman for the LNA said in a statement, without giving any further details.

The LNA has already entered the outskirts of Sebha, the biggest city in Fezzan, and will now push further south to secure its oil-producing regions, a spokesman for the militia was reported saying on 15 January.

Sebha lies a few hundred kilometres east of Sharara, an oil field, which has been shut down since early December by protesters. At 350,000 barrels a day (b/d), Sharara is the largest oil field in the country, and its closure has been costing Libya most than $32m a day in lost export revenues.

Led by Khalifa Haftar from the eastern city of Benghazi, the LNA has long mooted operations in the south, and has made a number of announcements regarding pushing towards the area. His forces already control the key eastern oil export terminals. The LNA is now deploying substantial forces, including more than a hundred armoured vehicles, and has taken control of two airbases.

However, it is likely to meet resistance from the well-armed Tebu forces in the area.

“I think the LNA will circumvent Sebha," says Jelal Harcahoui, a lecturer in geopolitics at the Universite Paris-Est Marne la Vallee. "The Tebus there will be too hard to dislodge. My anticipation is that the LNA will flex its muscles further south of Sebha.”

Since the fall of Muammar Gadaffi in 2011, southern Libya has become synonymous with lawlessness, from kidnappings to people smuggling. The region is fragmented by autonomous militias, with each seeking legitimacy and funding. Acute shortages of fuel and basic necessities have added to the sense of neglect.

Most residents in the south are increasingly distrustful of all northern powers, whether the internationally recognised Government of National Accord (GNA) or Haftar’s LNA. The militia’s entry into Fezzan will only complicate matters.

Securing Fezzan, with its major oil fields, will be key to Libya’s economic survival. The Central Bank of Libya said earlier this month that its deficit in 2018 stood at LD4.6bn ($3.3bn), down from LD10.6bn in 2017 due to higher oil prices.

Libya received $24.2bn in 2018 oil revenue; this was about $4.7bn more than expected due to the higher oil prices. But more than half the country’s LD$30.7bn expenditure for the year was spent on salaries, and another $5.7bn was spent on government subsidies, while just $2.5bn went to development projects,

The rise in revenues came despite the most recent shutdown of the Sharara oil field in December, and major disruptions in the eastern oil ports in the summer.

Mustafa Sanalla, chairman of the National Oil Corporation (NOC), announced the state oil company had “achieved its highest levels of production and revenues since 2013”. Before the closure of Sharara, Libya’s oil output had been averaging more than 1.25 million b/d, its highest level in years.

Sanalla has insisted NOC will not restart Sharara until the field’s security apparatus is reformed. With facilities spread across the remote desert of the southwestern Murzuq basin, the field has seen several closures over the past few years due to worker protests and attacks by tribal militias on export pipelines.