Security was tight in Hong Kong and activists faced pressure from police on the 36th anniversary of China's bloody 1989 crackdown on pro-democracy demonstrators in Tiananmen Square, which Taiwan and the United States said must never be forgotten.

China has never provided a full death toll, but rights groups and witnesses say the figure could run into thousands. Public discussion of what happened is taboo in China, which blamed the protests on counter-revolutionaries seeking to overthrow the ruling Communist Party.