Ten workers from Venezuela’s oil industry, including the secretary general of the United Federation of Oil-Sector Workers of Venezuela, José Bodas, were detained early Monday.
They had demanded that a new collective bargaining agreement be signed, according to a report by El Universal.
The last agreement expired in October 2013.
Sources said the arrests happened during a general assembly held at the gates of Puerto La Cruz refinery in northeast Venezuela.
The refinery is owned by Petróleos de Venezuela, S.A., the Venezuelan state-owned oil and natural gas company.
Other Venezuela labor unions expressed concern about Bodas’s arrest.