Protesters blocked an oil tanker from loading at the Libyan terminal of Es Sider on Tuesday, the National Oil Corporation (NOC) media office and an engineer at the port said.
NOC is working with the Petroleum Facilities Guards to end the blockage, the NOC media office said.
Earlier, two engineers at Ras Lanuf said another tanker there had also been blocked, but it was later allowed to resume loading.
Protesters who said they wanted jobs for local people and changes to the leadership of NOC blocked the ports last week but the company said on Friday they had been reopened.
Exports have also been stopped at Hariga, another Libyan oil terminal. Last year, eastern-based forces in Libya’s civil war blocked nearly all oil exports for months.
(Reuters)