The outpouring of discontent underscored tensions between China and the vibrant city of 7 million that was returned to China in 1997 after more than a century of British colonial rule.

While much of it revolves around inequality and stunted democratic development, Hong Kongers are also upset over what they see as arrogant Chinese behaviour — mainlanders taking over retail outlets during shopping trips or even the choice of language during the swearing-in, Beijing-accented Mandarin instead of the Cantonese dialect spoken locally.

Leung Chun-ying (57) became third chief executive after Donald Tsang and Tung Chee-hwa. He promised to address economic needs, including skyrocketing housing prices, which many blame on deep-pocketed mainland apartment buyers.

A demonstrator who tried to interrupt Chinese President Hu Jintao as he began his address was bundled away by security officials. The man, one of the guests invited to the inauguration, waved a small flag and yelled slogans calling for China’s leaders to condemn the brutal June 4, 1989, crackdown on protesters in Tiananmen Square. He also called for an end to one-party rule in China. Mr. Hu took no notice.

The protesters jammed the route of the march, a series of thoroughfares bordered by high-rise apartments and office buildings. There was occasional tension with the thousands of police officers deployed, but by and large the event went off peacefully.

Mr. Hu said Hong Kongers now have more rights and freedoms than ever, a reminder that China has largely kept the promise it made when it regained the territory from U.K. to keep Hong Kong’s relatively open political system in place for 50 years.

But that did little to assuage the protesters, who see China’s Communist Party rule as strongly at odds with the values that many inherited from a British-influenced education, and the continuing spread of democracy to neighbours like S. Korea and Chinese-speaking Taiwan.

“China’s way of thinking is totally different from ours,” said Bono Lau (46). “Tung Chee-hwa talked about one country, two systems but there’s no more of that nowadays.”

Calls for democracy have been catalysed by the stunted election that catapulted Mr. Leung to power and by corruption scandals surrounding his predecessor.

Hong Kongers fear that the political system in place since 1997 has resulted in the city’s billionaire tycoons having too much influence over senior government officials.

Government data now show that income inequality has risen to its highest level in four decades.

More In: International | News