The warning came as protesters fought with police throughout the city this past week
Police launched tear gas and rubber bullets at protesters who built barricades on the campus of the Chinese University of Hong Kong,
Previously in the day, more than 1,000 protesters assembled in central Hong Kong in the lunch hour impeding roads throughout the city.
The demonstrators, dressed in office garments, were observed, yelling: "Fight for freedom, stand with Hong Kong!"
The demonstrations come just a day after the territory saw a marked escalation in violence, with police shooting one activist in the torso. A pro-Beijing supporter was set on fire by anti-government protesters.
The protests started in June against a now-withdrawn plan to allow extradition to mainland China, but have since morphed into more extensive demonstrations, with activists demanding greater democracy and police accountability in Hong Kong.
On Tuesday afternoon, police spokesman Kong Wing-Cheung hit out at the protesters, saying they had "countless examples of rioters using random and indiscriminate #violence against innocent" people.
"Hong Kong's rule of law has been pushed to the brink of total collapse as masked rioters recklessly escalate their violence under the hope that they can get away with it," he told reporters, adding that Monday's attack on the pro-Beijing supporter was being investigated as attempted murder.
Steve Simmonds