Lee Cheuk-yan, the chairman of the Hong Kong Alliance in Support of Patriotic Democratic Movements in China, takes part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

A man wearing a protective face mask looks on as protesters take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

A protester wearing a protective face mask pushes down barricades to attend a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

A person wearing a protective face mask waves a Hong Kong independence flag as protesters take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks gesture as they take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters sit on barricades as they attend a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wave Hong Kong independence flags as they take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Lee Cheuk-yan, the chairman of the Hong Kong Alliance in Support of Patriotic Democratic Movements in China, takes part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

A protester raises his British National Overseas (BNO) passports during a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters wearing protective face masks and coverings wave Hong Kong independence flags as they take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.

Protesters take part in a candlelight vigil to mark the 31st anniversary of the crackdown of pro-democracy protests at Beijing's Tiananmen Square in 1989, after police rejects a mass annual vigil on public health grounds, at Victoria Park, in Hong Kong, China June 4, 2020.