The Netherlands data protection regulator has fined ride-hailing app, Uber for a "serious violation" of the rules by transferring data about its drivers to servers in the United States.

The regulator hit Uber with a 290 million Euro penalty for a breach of the European Union's General Data Protection Regulation.

The Dutch Data Protection Authority (DPA) said Uber collected European drivers' sensitive information. 

This included taxi licenses, photos, payment details, location information, identity documents, and in some cases even criminal and medical data of drivers.

Over two years, the DPA said, the information was transferred to Uber's US headquarters without using transfer tools that filter information.

Uber said it would appeal the fine.