An explosion at the alkylation plant of Pemex's Antonio Dovali Jaime refinery in Salina Cruz, Oaxaca, left three workers injured, Mexican newspaper El Universal reported.
Three of about 10 refinery piping-section maintenance workers suffered burns, the newspaper reported, citing witnesses. The report said the injured were taken to a Pemex hospital.
Pemex did not immediately respond to a Reuters request for comment.
In May, Pemex had reported the death of a worker injured in an explosion at the Oaxaca refinery.