East Libyan forces said on Thursday they had rapidly retaken control of large areas of the closed oil ports of Es Sider and Ras Lanuf, which they retreated from a week ago in the face of an armed attack.
Local witnesses and military sources said forces loyal to eastern commander Khalifa Haftar had retaken oil storage tanks and Ras Lanuf airstrip, and that Es Sider port was under military control as clashes continued and troops advanced west.
The violence at the oil terminals has caused "catastrophic damage", according to the National Oil Company.
The latest clashes began last Thursday when armed groups led by militia leader Ibrahim Jadhran attacked two northeastern oil facilities controlled by Haftar's self-styled Libyan National Army.
Jadhran's Petroleum Facilities Guard controlled the oil terminals for years following the 2011 ousting of Gaddafi – but they were eventually forced out by the LNA in September 2016.
In a video posted last week on social media, 35-year-old Jadhran – a member of the Al-Magharba tribe, largely based in the oil crescent – said he had formed a new alliance to take control of the crude corridor.
The flare-up comes just weeks after rival Libyan leaders sparked hope of progress for their conflict-wracked nation by agreeing during a French-led summit in Paris to hold nationwide elections in December.
The deal struck by four key powerbrokers – including Haftar and the head of an internationally backed government in Tripoli – was in line with a United Nations plan to stabilise the country.
But scepticism was high from the start and experts say the latest clashes underscore how little the political push has impacted the situation on the ground.
Federica Saini Fasanotti, of the Washington-based Brookings Institute, said there are "two different realities" when it comes to Libya.
"One is made by international agreement, conferences… and many, too many, words in the sky," she said.
"The other one is made by simple facts on the ground."