BENGHAZI, Libya (Reuters) - East Libyan forces carried out a fifth day of air strikes on Tuesday against a rival faction that overran the major oil ports of Es Sider and Ras Lanuf, officials and residents said.
The eastern-based Libyan National Army (LNA) and the Benghazi Defence Brigades (BDB) have been battling for control in Libya's eastern Oil Crescent since Friday, threatening production from oil ports that the LNA seized in September.
A senior official from Libya's National Oil Corporation said on Monday that production had dipped by 35,000 barrels per day (bpd) due to the latest unrest, leaving national production at just over 660,000 bpd.
OPEC member Libya was producing more than 1.6 million bpd before a 2011 uprising led to political turmoil and conflict that slashed output to a fraction of earlier levels.
LNA spokesman Ahmed al-Mismari said the latest strikes had hit targets from the Benghazi Defence Brigades (BDB) at Ras Lanuf and at Nawfiliya, 75km (46 miles) to the west.
"It forced them to mobilise ambulances to carry their dead and wounded to the west," he said.
A resident and a military official in Ras Lanuf confirmed the air strikes, but said there had been no change to the positions of the rival factions on the ground.
A social media account used by the BDB said the group "is protecting all its positions, and controls the area from Nawfiliya to beyond Ras Lanuf".
Since the BDB attacked on Friday, a front line has formed at the centre of the Oil Crescent, between the ports of Ras Lanuf and Brega. The LNA still controls Brega as well as a fourth port, Zueitina, which lies to the northeast.
It says it is using air strikes to prepare the ground for a counter-attack.
The LNA ended long blockades at Zueitina, Ras Lanuf and Es Sider when it took them over seven months ago, leading to a sharp boost to Libyan oil production.
Es Sider and Ras Lanuf were badly damaged in previous rounds of fighting and are still operating well below capacity.
Reporting by Ayman al-Warfalli and Aidan Lewis; Editing by Alexander Smith