Two executives of Uber were arrested in France on Monday, according to multiple reports.

Uber France CEO Thibaud Simphal and Uber Europe GM Pierre-Dimitri Gore-Coty were taken into custody for questioning over "illicit activity," a spokeswoman for the Paris prosecutor told the BBC.

TechCrunch reported Monday that the executives have been charged with running illegal taxi operations and with concealing digital documents.

Uber did not immediately respond to a request for comment on Monday, according to the Associated Press, but officials last week vowed to keep operating the lowest-cost UberPop service until France's top court rules on it.

A spot check of the app on Monday showed drivers available in central Paris, the AP said.

After French taxi driver protests against Uber turned violent last week, the country's interior minister asked Paris police to ban the low-cost service, according to CNN.

San Francisco-based Uber operates in about 300 cities worldwide and may be the most valuable venture-backed startup in history.

The company last month expected to raise between $1.5 billion and $2 billion in new funding that would value the company at $50 billion or higher, according to The Wall Street Journal.