Officials in the Mexican resort of Cancun and nearby cities have rounded up scores of Uber cars and taken them to impound lots until drivers pay fines of about $2,800 apiece.

The government of the Caribbean coast state of Quintana Roo says the ride-sharing service is illegally offering transport services.

Uber says about 100 of its drivers' vehicles had been impounded in the last week and 96 of them were carrying Cancun residents, not tourists.

Uber says the fines are exorbitant and alleges there had been "threats and violence against drivers, customers and tourists."

State transportation secretary Jorge Portilla says Uber violated a state law prohibiting unlicensed transport services, and that Uber knew about the law beforehand.

Portilla says Uber has affected the incomes of registered taxi drivers.