A file illustration picture shows the logo of car-sharing service app Uber on a smartphone next to the picture of an official German taxi sign in Frankfurt, September 15, 2014. [Photo/Agencies]

GUANGZHOU - The office of US taxi-hailing app Uber in southern Chinese city of Guangzhou was raided on Thursday, with a number of mobile phones seized, a city official confirmed on Friday.

The company is suspected of unlicensed operation and conducting illegal business by allowing private car owners to offer taxi services, an official with the city's traffic authority told Xinhua.

The official said Uber was not specifically targeted in the raid, which was part of a comprehensive crackdown on illegal taxi services by private drivers.

China bans unlicensed private cars from offering taxi services, but booming market demand has fueled the popularity of illegal service providers, often sparking anger among licensed taxi drivers who protest squeezed profits caused by unfair competition from private car owners.

In January, the Ministry of Transport ordered app developers to exclude private cars from their platforms and ensure that all vehicles are owned by taxi or car-hire companies for passenger safety.

The Uber service was still available in Guangzhou as of Friday. An Uber spokesperson said the company's services have not been affected, and they are actively communicating and cooperating with authorities.

Thursday's raid was met with mixed reactions. While taxi drivers have praised the "execution of justice," many members of the public have complained about a lack of taxi services by licensed drivers.

A statement by the Guangzhou municipal transport commission said it has noticed the failure of traditional taxi services to meet public demand and the commission is developing new Internet-based and legal services.