Fierce clashes broke out in the oil crescent region between so-called Petroleum Facilities Guard and Khalifa Haftar's militia groups on Saturday.
Haftar's militias launched early in the day a military operation under the name "Surprise Lightening" to take control of Brega, Zuwetina, Sidra and Ras Lanouf oil terminals, all are under the control of Ibrahim Jodran's PFG.
There are conflicting reports about the takeover. Haftar's militias claimed full control of Sidra and Ras Lanouf terminals, but the PFG denied it and confirmed clashes are still ongoing.
The PFG said Haftar's militias are backed by rebels from the Sudanese Justice and Equality Movement.
Plumes of black smoke billowed into the air from Sidra terminal.