MEXICO CITY -- Mexico's state oil company says it is working to resupply gas stations in several states after days of shortages caused by an increase in fuel thefts from pipelines.

Petroleos Mexicanos said in a statement Thursday that its trucks are hauling fuel to stations 24 hours a day in an effort to stem shortages in the state of Nuevo Leon.

In statements earlier this week, Pemex blamed illegal taps of five different fuel pipelines for the shortages affecting several northern and western states. It said it had ordered additional gasoline imports to make up the difference.

The shortages affect major urban areas including Guadalajara, Monterrey and Saltillo.

In February, Pemex announced that it would no longer ship finished, usable gasoline by pipeline because of the thefts.