Thousands of Hong Kong university and school students swapped classes for democracy demonstrations on Monday, the latest act of defiance in an anti-government movement that has plunged the Chinese-ruled city into crisis. The boycott follows a weekend marred by some of the worst violence since unrest escalated more than three months ago, with protesters burning barricades and throwing petrol bombs, and police retaliating with water cannon, tear gas and batons. Thousands of students gathered on the hilltop campus of Chinese University under leaden skies, taking turns to make speeches from a stage with a black backdrop embossed with "Students in Unity Boycott for our City". They are seeking greater democracy for the former British colony which returned to China in 1997 under a "one country, two systems" formula that guarantees wide-ranging autonomy, including the right to protest and an independent judiciary. They fear those freedoms are being slowly eroded by Communist Party rulers in Beijing, a charge China denies. "I come here just to tell others that even after summer holidays end we are not back to our normal life, we should continue to fight for Hong Kong," said one 19-year-old student who asked to be identified as just Chan. "These protests awaken me to care more about the society and care for the voiceless." On the first day of the new school year, secondary students were seen singing, chanting and forming human chains, some wearing hard hats and masks. Many primary schools were closed because of a typhoon warning. China accuses Western countries of egging on the protests. It says Hong Kong is its own internal affair. Chinese Foreign Ministry spokesman Geng Shuang reiterated Beijing's support for Hong Kong leader Carrie Lam. "China's central government supports chief executive Carrie Lam's leadership ... to administer in accordance with the law and supports Hong Kong's police tackling the violence and chaos in accordance with the law to restore order," he told a press briefing. Several editorials in Chinese state media condemned the protesters. One published by the state news agency Xinhua warned that "the end is coming" for protesters who should "never misjudge the determination' of the central government. -Reuters