Oil workers in Gabon began an open-ended, industry-wide strike on Monday night after talks with the government collapsed, union ONEP said, and long queues formed at gas stations on Tuesday on fear of shortages.
The trade union had been in negotiations with authorities of the Central African country for several weeks, demanding the reinstatement of some workers who had been fired by oil companies, among other issues.
"The national bureau informs you of the start of an unlimited general strike in all oil sector companies and related activities operating in the national territory from Monday Dec. 1 at midnight," said a union statement addressed to the workers and seen by Reuters.
Long queues formed at petrol stations in the capital on Monday as consumers scrambled to fill their cars and get reserves before the strike depleted supplies.
Government officials could not immediately be reached to comment.
ONEP, the umbrella union for the oil trade, represents a majority of its more than 5,000 workers. In a separate letter to Gabon's prime minister, ONEP said it would return to talks only if the government met four demands.
They included the immediate suspension of some salary deductions and the lifting of sanctions by oil firms Perenco and STSI Boccard on some workers.
The union also called for the manager of STSI Boccard, which is subcontracted by French oil giant Total, to be expelled from the country, as well as the departure of the director general of Libya Oil Gabon.
Total and Royal Dutch Shell dominate the former OPEC member's roughly 230,000 barrels per day oil sector, while smaller players include Maurel & Prom, Perenco and Addax.
Reporting by Gerauds Obangome