U.S. regulators accused Fiat Chrysler Automobiles of violating emissions standards in more than 100,000 diesel vehicles in an alleged scheme that bears similarity to the scandal that engulfed Volkswagen Group and cost the German automaker billions of dollars.

The Environmental Protection Agency said Thursday that Fiat Chrysler installed software on about 104,000 pickup trucks and sport-utility vehicles to cheat emissions standards.

The allegations cover the 2014, 2015 and 2016 Jeep Grand Cherokee and light-duty Ram 1500 trucks with 3-liter diesel engines.

The EPA said the automaker installed eight different software programs on the vehicles that collectively allowed the vehicles to spew harmful nitrous oxide emissions, which can exacerbate breathing conditions.

"This is a clear and serious violation of the Clean Air Act," Cynthia Giles, assistant administrator for EPA’s Office of Enforcement and Compliance Assurance, told reporters. "There is no doubt they are contributing to illegal pollution."

Fiat Chrysler shares traded in New York plunged 10.4% at 10:37 a.m. to $9.94.

The EPA has the authority to fine automakers up to $37,500 per vehicle for violations of the Clean Air Act, meaning the scandal could cost the Italian-American more than $3.75 billion in civil penalties. The agency threatened possible fines on Thursday if it determines that the software installed on the vehicles qualify as illegal "defeat devices" under U.S. laws.

The agency said it discovered the alleged violations after expanding its testing of on-road vehicle performance following the Volkswagen scandal.

VW pleads guilty to conspiracy, obstruction of justice; 6 execs charged

Volkswagen admitted to cheating emissions laws on more than half a million vehicles and has since agreed to criminal and civil settlements totaling nearly $22 billion. Six VW executives were charged Wednesday with allegedly weaving a conspiracy to dodge regulations while the company pled guilty to similar charges on a corporate level.

Spokespeople for Fiat Chrysler did not immediately comment.

Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.