Students gathered to mark the death of Hu Yaobang on 15 April 1989
The 20th anniversary of the death of reformist Chinese leader Hu Yaobang has passed without being marked in China.
The anniversary is seen as the start of an ultra-sensitive period for Beijing, in the run-up to the 20th anniversary of the 1989 Tiananmen Square protests.
It was Hu's death that set in motion the chain of events leading to the 4 June crackdown.
Meanwhile students in Hong Kong are holding a vote on whether China should apologise for the Tiananmen killings.
A student union president is facing a vote of no-confidence over the issue.
Mr Hu was ousted as Communist Party chief in 1987 for his perceived weakness during protests the previous December, and his attempts at reform.
Hu Yaobang's attempts at political reform lead to his sacking
When he died on 15 April 1989, mourners gathered and called for his rehabilitation.
By the eve of his funeral on 21 April, 200,000 students rallied in Tiananmen Square, demanding fresh political reforms.
China's leadership dithered, but eventually declared martial law.
Protests grew throughout May 1989 until early June, when troops were sent in killing hundreds, perhaps thousands of protesters.
Twenty years on, Mr Hu's death was not marked in China, and the anniversary of the Tiananmen killings is also expected to pass without official acknowledgement.
Officially, the protests are viewed as counter-revolutionary, and their repression is seen as justified, BBC Beijing reporter Quentin Somerville says.
The Communist Party says political instability would have made it impossible for China to achieve economic success.
Hong Kong vote
The former British colony of Hong Kong is the only place in China where the events of 1989 are likely to be openly commemorated.
Students at several Hong Kong campuses are split between those who wish to mark the anniversary of the crackdown and those who wish to tone down criticism of the government in Beijing.
"After 20 years of denial and injustice, the world has had enough," the Hong Kong University (HKU) student union said in explaining its three-day poll on the issue, which ends on Thursday.
The HKU union leader, Ayo Chan Yi-ngok, is under pressure after saying that some student leaders in the 1989 protest had acted irrationally.
Leading a no-confidence vote against him is Christina Chan Hau-man, the university student who wrapped herself in a Tibetan flag during the Olympic torch relay through Hong Kong last May.
At the City University, a plan to issue a booklet about the Tiananmen Square protests was initially quashed by students who said the 1989 events were of little relevance.
The booklet will now be made, after students from eight universities in Hong Kong criticised what they said were efforts to suppress freedom of speech.