China is marking the 20th anniversary of the handover of Hong Kong from the British.

But, a day ahead of a visit from President Xi Jinping, pro-democracy activists occupied the golden "forever blooming golden bauhinia" - a symbol of Hong Kong and a monument to the reunification.

Several well-known democracy activists were arrested, including student leader Joshua Wong.

The protesters also called for the release of imprisoned Chinese activist Liu Xiaobo, who has been diagnosed with cancer.