MEXICO CITY — Mexico City's stubborn air pollution problem has a new cause: gasoline and diesel spewing from illegal taps drilled into government pipelines to steal fuel.

Taps have increased in the city and its suburbs, and one came close to causing a pollution alert on Thursday.

The environmental commission for the metropolis said a 60-foot (20 meter) tall geyser of gasoline spewing from an illegal pipeline tap brief pushed ozone levels above limits.

An air pollution alert was avoided because winds quickly dispersed the gas.

Such illegal taps were once rare in Mexico City and the surrounding State of Mexico.

But in the first three months of 2018, 61 taps have been found in the city and 315 in the state, compared to six and 234 in the same period of 2017.