A pipeline explosion north of Mexico City that killed at least 73 people has confronted President Andres Manuel Lopez Obrador with the biggest crisis since he took office pledging to crack down on graft and fuel theft.

Petroleos Mexicanos said its specialists and local officials were working to deal with a fire caused by the illegal tap on the gasoline line in Tlahuelilpan, part of a fuel-theft industry valued at an estimated $3.5 billion. Pipelines were illegally siphoned an average of 41 times a day during the first 10 months of 2018, a 45 percent increase from last year, according to Pemex.

Lopez Obrador, who took office in December, said he won't be stymied in his offensive against fuel-theft gangs. His plan, which involves increasing surveillance along pipelines and more shipments by tanker trucks, led to gas shortages at filling stations across central Mexico.