Libyan tribesmen staged a demonstration at the eastern oil port Hariga on Thursday in protest against the appointment of a government minister, a leading member of the tribe said.
It was not clear whether the action affected oil exports from the port in Tobruk near the Egyptian border.
A spokesman for port operator AGOCO, part of state oil firm NOC, declined to comment.
“We are at the port’s gate. No car can enter or leave,” a member of the powerful Obeidat tribe told Reuters, asking not to be identified.
He said tribesmen were protesting against a decision by the internationally recognised government in Tripoli to appoint Ali Essawi as economy minister.
Hariga is in eastern Libya, run by a rival administration.
Libyan prosecutors in 2011 named Essawi as the main suspect in the killing of Abdel Fattah Younes, a former top rebel commander during the uprising against Muammar Gaddafi in 2011.
Younes belongs to the Obeidat tribe.
A Libyan court in 2012 dropped the case against Essawi and other suspects. He re-emerged in the spotlight when Tripoli-based Prime Minister Fayez appointed him as economy minister this month.
Khalifa Haftar, a top commander whose troops control the east, ordered a new investigation into the killing of Younes. His killing caused deep rifts in the rebel camp which later took over the east of the oil-producing country.
Younes was part of Gaddafi’s inner circle.
He defected at the start of the uprising in February 2011 and became military chief of the rebellion, a move opposed by other rebels who suffered under the old regime.
The circumstances of his killing remain murky, but it is known he was slain in July 2011 after rebel leaders summoned him back from the front line to Benghazi.
Separately, gunmen stole two company cars at a control station of Libya’s giant El Sharara oilfield on Thursday, a field engineer said.
Output was not affected, he added. The field typically produces around 300,000 barrels a day.
Station 186, 40km from the main part of the field deep in the southern desert, has been attacked by gunmen several times.
In July, two staff, one a Romanian, were kidnapped there and have not been heard from since. Output dropped temporarily by around 160,000 barrels a day after the attack, leading to a shutdown of the station before recovering to former levels.
Tripoli-based NOC operates Sharara in partnership with Repsol, Total, OMV and Equinor, formerly Statoil.
Last week, NOC staff staged small protests at three fields demanding salary increases, better work conditions and security.