Taiwan urges more democracy for Hong Kong after Xi Jinping's speech

"Any activities endangering the country's sovereignty, challenging the central government and Hong Kong Basic Law, a semi-constitution subordinate to the Chinese constitution, or committing an act of sabotage against the mainland are crossing the red line and utterly intolerable", said Xi.

The central government will unswervingly implement the policy of "one country, two systems" and make sure that it is fully applied in Hong Kong without being bent or distorted, he said.

Xi said that any threats to the authority of China's communist party government "cross the red line and are absolutely impermissible".

"My priority will be to heal the divide and to ease the frustration - and to unite our society to move forward", Chief Executive-elect Carrie Lam said in March after her selection by a 1,200-person election committee stacked with Beijing loyalists.

The strong words were used by Chinese President Xi Jinping when he was speaking during the swearing in ceremony of the new Hong Kong government.

Tensions are set to increase, as the pro-democracy groups threaten to bring 100,000 people onto the streets for the 20th anniversary celebrations later today.

In Saturday's protests, pro-democracy party Demosisto said police had arrested five of its members, and four members from the League of Social Democrats. Hong Kong has more than 3 million registered voters.

Leaders including high-profile campaigner Joshua Wong were detained and bundled into police vans as their supporters shouted "shame".

The July 1 rally at Victoria Park takes place each year in protest of the 1997 handover of Hong Kong to Chinese rule.

In her address, Lam also recognised the challenges that Hong Kong is facing but added that the territory's problems can not be solved overnight and she needed everyone's help.

He was briefed on how the Hong Kong Special Administrative Region Government, through investment in infrastructure, is enhancing its connections within the Guangdong-Hong Kong-Macao Bay Area as well as with the rest of Mainland, and on the strategy of strengthening Hong Kong as an worldwide and regional logistics hub.

Earlier in the morning, he officiated at the raising of the Chinese flag and the inauguration of Hong Kong's new leader Carrie Lam.

However, he said Hong Kong had to do more to shore up security and boost patriotic education, in a veiled reference to legislation long-delayed by popular opposition.

The Sino-British Joint Declaration, signed in 1984 by then-British Prime Minister Margaret Thatcher and Chinese Premier Zhao Ziyang, laid out how Britain would end its century-and-a-half long rule over Hong Kong.

A huge security operation has shut down large parts of Hong Kong, with thousands of police deployed to keep away demonstrators angry at Beijing's tightening grip on the freedoms of almost eight million people.

Ron Wong, 17, who was marching with his parents, said Xi's visit had been a "show of power of who's in charge".

Associated Press photographer Kin Cheung has documented Hong Kong's transition to Chinese rule with several pairs of abstract photos based on daily life and local symbols.

March organizer Au Nok-hin called on people to stand up for Hong Kong's rights and freedoms under the terms of the handover treaty, which China dismissed on Friday as "a historical document. with no practical application", and which the United Kingdom said is still valid.

Many participants said they were marching in support of imprisoned Chinese Nobel Peace Prize laureate Liu Xiaobo, who has been diagnosed with late-stage liver cancer.

  • Rogelio Becker