As Hong Kong begins to mark the 15th anniversary of British handover of the colony to the Chinese on Sunday, protesters were targeting Chinese President Hu Jintao who was leading the events.
Hu swore in a new leader, Leung Chun-ying, for Hong Kong who will have to grapple with a number of challenges including human rights.
The demonstrators are demanding democracy and want China to stop interfering in the local affairs.
Leung was made chief executive by Beijing-backed elites and the protesters want an end to rule of a single-party system.
Leung's loyalty to Beijing was evident from the very language he uttered, not a single word of the official language of Hong Kong Cantonese, but only Mandarin Chinese. Cantonese is the major language in Hong Kong where close to 90 percent of the population speak that language.
The new chief executive, a millionaire, has been marred by scandals over an illegal construction before struggling to get to the top post.
The Chinese president once again insisted on the "one country, two systems" model in Hong Kong upholding the previous set-up which came into effect in 1997.
In his speech he said: "It has maintained its status as an international financial, trade and shipping centre. It has developed closer links with the mainland and broader contracts with the world. What has happened shows that "one country, two systems" is the right policy for Hong Kong and it is a policy full of vitality. It also shows that Hong Kong compatriots have the wisdom and capacity to manage, build and develop Hong Kong well," according to People's Daily.
During his speech, Hu was heckled by a protester who shouted against Chinese interference was promptly removed by the security personnel.
The event venue was secured by thousands of security officials and barricades were also in place to thwart mass protests.
Hours prior to the inaugural event, protesters were demonstrating and shouting slogans against Hu near the venue. Protesters were shouting "Battle the Communist Party! We will battle to the end!" and were seen burning Leung's pictures, according to an AFP report.
Scores of demonstrators have also been detained by the Hong Kong police. Reports suggest pepper sprays were used against the protesters.