Roughly 500 people were arrested at a massive sit-in in Hong Kong on Tuesday to protest increasing infringement by the mainland Chinese government. Hong Kong, which has had relative autonomy since being returned to China from the British in 1997, was recently told by Beijing that it holds the ultimate authority over the capitalist city. Arrests at the protest marking the anniversary of the end of British rule were for unauthorized assembly and obstructing police officers. Organizers claimed 510,000 people attended, while police say there were 98,600 people. The protest came a day after 800,000 people voted in an unofficial referendum to have direct nominations and elections of Hong Kong’s chief executive, something Beijing has promised by 2017.