Chinese President Hu Jintao swore in Hong Kong's new leader Sunday, on the 15th anniversary of the former British colony's return to Chinese rule, even as anti-government protestors tried to disrupt Hu's visit.

Speaking at the inaugural ceremony of the fourth-term government of the Hong Kong Special Administrative Region (SAR) and the swearing-in of Chief Executive Leung Chun-ying for a five-year term, Hu said Hong Kong's remarkable achievement proves that the one country, two systems is the best and stable solution for Hong Kong, Xinhua news agency reported.

A lone protester stood up and shouted during Hu's speech, demanding an end to one-party rule and dictatorship in China, but he was quickly escorted out of the hall, which was under tight security.

Hu expressed confidence in Hong Kong's role as a free society and responded to recent tensions with a call for unity. He called on the administration of Leung to heed deep disagreements and problems in the territory.

Never before have Hong Kong residents enjoyed the range of democratic rights and freedoms as they do now, said Hu.

The president said the citizens of Hong Kong are now masters of their own fate and they exercise control over their affairs that fall within the purview of the SAR.

We should continue to advance the democratic process in Hong Kong as provided for in the Basic Law and the relevant decisions of the Standing Committee of the National People's Congress, Hu said.

Demonstrators who were demanding an investigation into the suspicious death of Tiananmen Square activist Li Wangyang, which caused an uproar in Hong Kong, tried to disrupt Hu's visit. Hong Kong police thwarted the demonstrators' efforts to approach the venue using pepper spray, even as several demonstrators were taken away in police vehicles.

The protests that greeted the Chinese president over the weekend are a far cry from Hu's last visit five years ago, when he toured Hong Kong in a blaze of pre-Olympic glory, a BBC correspondent said in a report.

 Hong Kong's new leader said his administration would promote democracy and robust economic development.

 The government must assist investors and enterprises, large and small, to seize opportunities arising from our nation's and the world's economic growth, Leung said. We must capitalize on the opportunities to consolidate and elevate Hong Kong' s status as an international financial center and help the shipping industry to restructure and upgrade. We must also fully implement all economic and trade agreements signed with mainland counterparts to expand job opportunities and development potential in the mainland for Hong Kong people.

The new administration has been sworn in at a time when Leung's popularity ratings have been hit by a construction scandal, growing wealth gap and corruption.