The state Civil Protection agency reports via Twitter that people were treated for burns from the blast near the town of Zapoapan.
Veracruz's Public Safety Department published photos showing a thick column of smoke rising from an agricultural field and some charred vehicles.
State-run oil company Petroleos Mexicanos said today's explosion was "caused by an illegal tap" and had been extinguished.
Fuel theft is a growing form of organized crime in Mexico estimated to cost the country about $1 billion a year.