HONG KONG — In a rare scene of disorder, authorities cleared out hundreds of protesters who blocked part of Hong Kong’s financial district early Wednesday, a high-profile reflection of rising anxiety over Beijing’s tightening grip on the little enclave of incomplete democracy at the southeastern edge of Communist China.
Police arrested 511 people who staged an unauthorized overnight sit-in on an avenue running through the heart of the city after a rally the day before in which tens of thousands of demonstrators marched in the streets to push for the right to elect their leader free of limits Beijing wants to impose.
The protesters wanted to occupy the street until 8, just before the height of rush hour, as a rehearsal for a larger demonstration planned by the group Occupy Central with Peace and Love to shut the financial district if the Hong Kong government fails to come up with satisfactory democratic reforms.
Police started moving in at about 3 a.m. to take people away from Chater Road after they ignored warnings. One by one, demonstrators who had locked arms with one another were forcibly removed by hundreds of officers and taken away, some carried off their feet, to waiting police vans.
The protest’s messy aftermath is the latest sign of worries that, with Hong Kong only a third of the way through a 50-year period in which mainland China is supposed to stay largely hands-off from the city’s affairs, Beijing is failing to keep its end of the bargain.
Organizers said 510,000 people — the highest estimate in a decade — turned out for Tuesday’s protest march, an annual fixture held on a holiday marking Hong Kong’s return to China in 1997. A big factor boosting turnout this year was the release last month of a policy document or ‘‘white paper’’ by China’s Cabinet stating that Hong Kong’s high degree of autonomy is not inherent but authorized by the central government.
The document, issued days before nearly 800,000 voted in an informal referendum by Occupy Central to bolster support for democracy, was seen as a veiled warning that only intensified fears that Hong Kong would never get genuine democracy. Beijing authorities have promised to allow the city to elect its leader starting in 2017 but only if they can approve the candidates, which many reject.
‘‘We may think that Hong Kong without democracy still has freedom. However, after the Chinese Communist Party published the white paper, it showed that if we don’t take any actions and respond to the CCP, the existing rights and freedoms will be eliminated rapidly,’’ said Joshua Wong, convener of Scholarism, one of two student groups organizing two sit-ins. The 17-year-old’s group camped outside the office of Hong Kong’s Beijing-backed leader, Leung Chun-ying, where police did not intervene.