A black wreath flies to mark the 18th anniversary of a bloody crackdown on peaceful protests in Tiananmen Square, Beijing.
Tens of thousands attended a candlelight vigil in Hong Kong - an annual event that is always well attended.
Hong Kong is the only part of China's territory that is allowed to commemorate the events of Tiananmen.
In Tiananmen Square itself, the day began as always with a flag-raising ceremony, watched by a small number of onlookers.
Security was reportedly tight around the square, which in 1989 was the scene of weeks of pro-democracy demonstrations.
On 4 June 1989, the Chinese government sent in its troops - leading to the deaths of many students and civilians.
Beijing has always refused to apologise, saying the action was necessary to stop what it called a counter-revolutionary uprising.