Two Pemex workers were injured during a fire at the Lázaro Cárdenas refinery in the Mexican state of Veracruz, the state oil company said in a statement.
The blaze broke out last Friday (Jan 17) while staff carried out maintenance of an electric motor recharge station, Pemex said.
The workers, David Alejandro Cruz and Saúl Martínez, were taken to a hospital in the city of Minatitlán in a "stable" condition, the firm added.
Pemex said investigations were ongoing into the cause of the incident.
The firm did not say if the refinery's operations had been affected.