Thousands of protesters descended on China's representative office in Hong Kong on Sunday, as anger over an extradition bill morphs into a fresh front against what many see as a broader erosion of freedoms by the city's political masters in Beijing. Millions have rallied over the past two months in an unprecedented show of force against Hong Kong leader Carrie Lam, triggering the worst social turmoil to rock the former British colony since it returned to Chinese rule 22 years ago. Black-clad activists, many wearing masks, defied police orders and marched beyond the official end-point of a rally that took place earlier in the day to make their way toward Beijing's Liaison Office, close to the heart of the financial center. When asked if the protesters would attempt to force entry into the building, one 30-year-old man dressed head to toe in black, said, "No," as he mimicked a throat-slitting action. "That would be the death of Hong Kong," he added. Some protesters pelted eggs at the walls of the Liaison Office, while others spray-painted graffiti in a direct challenge to the Communist Party in Beijing. Hundreds of riot police took up positions close to the Liaison Office. Nearby, activists daubed graffiti on massive concrete pillars leading up to it, with the words "Restore Hong Kong, Revolution of Time." Sunday's protest, which had proceeded peacefully along the police-mandated route, is the latest in a wave of unrest that has plunged the Asian financial hub into political crisis. Some held up banners that said, "LIAR" and "No excuse Carrie Lame". A poster plastered on a lamppost called for an "Investigation on police brutality". Many ignored the official end-point of the rally as the demonstrations show no sign of let-up, posing the greatest popular challenge to Chinese leader Xi Jinping since he took power in 2012. Authorities used blue and white water-filled barriers to barricade government and police headquarters, while global bank HSBC, in a rare move, pulled down large metal barriers on the street level of its gleaming skyscraper building. While most of the rallies have passed off peacefully, some have erupted into violence late at night when more radical protesters have clashed with police. The city's police force has come under scrutiny after officers fired rubber bullets and tear gas last month to disperse demonstrators in some of the worst violence to roil Hong Kong in decades. The police are struggling to cope amid haphazard decision-making, worsening morale and anger among rank-and-file officers that they are taking the public heat for government unpopularity, serving and retired officers, politicians and security analysts told Reuters. The latest protest comes a day after tens of thousands gathered to voice support for the police, whom some have accused of using excessive force against activists, and demand an end to the violence. Sunday's march focused on calls for the full withdrawal of the extradition bill, which would allow people to be extradited to mainland China for trial, and an independent investigation into complaints of police brutality. Other demands include charges against protesters to be dropped and universal suffrage. -Reuters