SHANGHAI, Aug. 29 (Xinhua) -- Shanghai police said they have launched an investigation into the alleged massive data breach of Huazhu Group Ltd., one of China's largest hotel operators.

An online post emerged Tuesday, containing nearly 500 million pieces of information related to the hotel group's customers, including registration information, personal data and booking records of the group's wide range of hotel brands.

According to Changning District police on Tuesday evening, they received a report from the hotel group and will crack down on any illegal information transactions. The police also urged companies to strengthen their protection against data breaches.

Huazhu has also started a self-inspection and hired a technology company to verify the source of the information being sold online.

Huazhu is a public company listed in NASDAQ and runs over 3,000 hotels in more than 370 Chinese cities. It operates more than a dozen brands such as French hotel group Accor's Mercure and Ibis hotels in China as well as Hanting and Crystal Orange.