GUANGZHOU, China — Chinese regulators have opened a cybersecurity review into U.S.-listed Boss Zhipin and subsidiaries of Full Truck Alliance.

The Cyberspace Administration of China (CAC) said the probe had been opened to “prevent national data security risks” as the crackdown on the country’s technology sector continues.

Yunmanman and Huochebang, subsidiaries of the New York-listed Full Truck Alliance were two of the firms named by regulators. Boss Zhipin, an online recruitment platform backed by tech giant Tencent and listed on the Nasdaq, was also targeted by the CAC.

During the cybersecurity review, these companies are not allowed to register new users.