Telegram, a popular encrypted messaging app, will allow users to cloak their telephone numbers to safeguard Hong Kong protesters against monitoring by authorities, according to a person with direct knowledge of the effort.

Axar.az reports citing Reuters that the update to Telegram, planned for release over the next few days, will allow protesters to prevent mainland Chinese and Hong Kong authorities from discovering their identities in the app’s large group chats.

Hong Kong’s Security Bureau told Reuters it has “been acting responsibly to deal with the current difficult time with a view to restoring the public order”. It declined to comment about whether it had tried to identify protesters by using the Telegram app.

China’s Foreign Ministry, the Cyberspace Administration of China (CAC) and the Hong Kong and Macau Affairs Office did not immediately respond to a request for comment outside of business hours.

Thousands of Hong Kong protesters take their cues from more than 100 groups on Telegram, according to protest organizers and supporters. Protesters use encrypted apps like Telegram to mobilize swiftly through multiple group chats, with less risk of police infiltration.