China's cyberspace regulator has proposed mainland companies pursuing share listings in the Hong Kong Special Administrative Region apply for cybersecurity inspections if they deal with data that concerns national security.

Large internet platforms planning to set up headquarters, operating or research centers abroad should also submit a report to regulators, the Cyberspace Administration of China said in the draft rules on Sunday.

The document revealed that internet platforms with more than 100 million daily active users would need to seek government approval when formulating operation rules, privacy policies, or making amending rules that could significantly affect user rights and interests.

Unless they have justifiable reasons, companies that provide instant messaging services should stop restricting users from accessing others or transferring files to other internet platforms, the regulator said.

The proposals are open to public review until December 13.

(With input from Reuters)