BENGHAZI, Libya (Reuters) - Eastern Libyan forces said they had reestablished control over two oil ports where an ousted faction launched a counter-attack on Sunday, briefly seizing one of the terminals.

A view of Es Sider export terminal in Ras Lanuf, where a North Korean-flagged tanker had loaded crude oil, March 11, 2014. REUTERS/Esam Omran Al-Fetori

The ports of Es Sider and Ras Lanuf were among four seized by forces loyal to eastern commander Khalifa Haftar’s Libyan National Army (LNA) on Sept. 11-12 from a Petroleum Facilities Guard (PFG) faction led by Ibrahim Jathran.

The fighting came as the state-run National Oil Corporation (NOC) prepared to restart oil exports from the ports, blockaded for several years.

The NOC said the Maltese-flagged Seadelta, which had been loading from storage at Ras Lanuf had withdrawn to a safe distance, but that it hoped normal operations would resume by Monday morning. The Seadelta was the first tanker to dock there for some two years.

LNA spokesman Ahmed al-Mismari said pro-Haftar forces had repelled an attack at Ras Lanuf with the help of air strikes, and were pursuing Jathran forces fleeing from Es Sider, where they had taken control earlier in the day.

A Libyan oil industry source confirmed that the LNA controlled both oil ports.

The clashes raise fears of a new conflict over Libya’s oil resources. Jathran’s PFG had aligned itself with a U.N.-backed government in Tripoli, while Haftar is a divisive figure whose opponents accuse of trying to establish military rule.

Fighting and political disputes have reduced oil output in the North African country to a fraction of the 1.6 million barrels per day the OPEC member produced before a 2011 uprising.

The NOC said Sunday’s clashes had set a previously damaged oil storage tank in Es Sider alight, but that firefighters had extinguished the blaze and no other damage to oil facilities had been recorded. Pictures from Ras Lanuf showed black smoke billowing from residential areas.

LNA spokesman Mismari and a pro-Haftar guard spokesman said LNA fighters had seen Jathran in clashes on Sunday and he had been injured in the shoulder. Jathran’s spokesman could not immediately be reached to verify the reports.

LNA forces later advanced about 30 km (19 miles) west of Es Sider to take control of the town of Ben Jawad, said Akram Buhaliqa, a second LNA official. At least four LNA fighters were killed, he said.

BLOCKADE

The LNA’s seizure of the ports a week ago took place as the Muslim holiday of Eid was starting and faced little resistance.

After moving into Es Sider, Ras Lanuf, Zueitina and Brega, the LNA said it was handing over control of the terminals to the NOC so that exports could resume.

Jathran had long blockaded three of the ports and a recent deal with the U.N.-backed government showed little sign of progressing.

On Thursday, the NOC announced it was lifting “force majeure” contractual clauses at the blockaded ports and that exports would restart immediately at Zueitina and Ras Lanuf.

It said they would start as soon as possible at Es Sider, and would continue at Brega, which had remained open. A tanker left Brega on Sunday loaded with 600,000 barrels of crude, headed for Italy, a port official said.

After the LNA took the ports, NOC Chairman Mustafa Sanalla had said Libya could raise output to 600,000 barrels per day (bpd) within a month and to 950,000 by the end of the year from about 290,000 currently.

But he said that would depend on new funds, and on the ports and blockaded pipelines being opened and remaining open.