Police said on Friday that they will be sending out SMS messages to the public during mass demonstrations, warning them to mind their safety.
The force said it understands that residents have been affected and their safety has been endangered during protests, especially when violence usually follows recent mass public assemblies.
To give more information to the people, police will be sending different messages to people on their phones, to raise their awareness and be vigilant about their safety.
But the force said due to the millions of phone users in the SAR, the reception time of the SMS messages may differ from person to person.
So people should also pay attention to the updates of other channels and from the government for the latest, it adds.
The police have defended their objections to the anti-extradition rallies and marches on Kowloon and Hong Kong Island in the coming weekend, citing the violence by protesters earlier.
Officers said they are concerned that radical protesters would "hijack" the events and put peaceful protesters, local businesses and residents in danger.