Hong Kong CNN  — 

The threat of violence hung over Hong Kong Thursday evening as thousands of student protesters prepared to face off with riot police, amid a continued occupation of several of the city’s most prestigious universities.

The level of unrest and destruction in the almost six-month-long protest movement has reached new and unnerving heights in recent days, with several people critically injured and Chinese state media warning radical protesters, “You are on the edge of doom.”

Sporadic clashes broke out Thursday morning, as police fired tear gas at protesters near the Hong Kong Polytechnic University in Kowloon. While on Hong Kong Island, roads surrounding the University of Hong Kong were blocked by protesters, resulting in traffic delays.

Universities have emerged as a new focal point of the protest movement, with numerous campuses across the city becoming home to heavily fortified temporary protest camps.

At the Chinese University of Hong Kong (CUHK) in the New Territories, several thousand protesters have effectively barricaded themselves inside the grounds, blocking all entrances for the third straight day.