4 June 2014 Last updated at 09:43 ET

Beijing tense on Tiananmen massacre anniversary

Chinese security personnel have swamped Beijing's Tiananmen Square on the 25th anniversary of the Beijing massacre.

Foreign journalists were ushered away from the square and passers-by were searched and had their papers checked.

In recent weeks, the authorities have detained dozens of activists to ensure their silence on the anniversary.

The 1989 protesters wanted political reform, but the crackdown was ordered after hardliners won a power struggle within the ruling Communist Party.

The authorities classify the 1989 protests as counter-revolutionary riots and hold no memorial.

In Hong Kong, however, thousands have gathered in a central park to participate in a Tiananmen remembrance rally.

Activist groups in Taiwan also marked the anniversary by erecting a huge image of Tiananmen Square during the crackdown.

Paramilitary police joined regular forces to control the square, in the centre of Beijing

But Chinese tourists thronged the square as usual, and seemed to notice little out of the ordinary

Both the Taiwanese and Japanese governments urged Beijing to use the memory of the protests to improve its attitude to human rights.

In the weeks before this year's anniversary, the Chinese authorities have detained lawyers, journalists and activists.

Rights group Amnesty International said in a statement that 66 people had been detained, questioned or had gone missing.

In a White House statement, the US called on the Chinese authorities "to account for those killed, detained or missing in connection with events surrounding 4 June 1989".

Internet search terms related to the 1989 massacre and the protests have been blocked, and access on Google has reportedly been restricted.

Relatives of those killed in the massacre were allowed to visit the graves of their loved ones under police guard.

Thousands gathered for a vigil in Hong Kong, which retains civil liberties not seen in mainland China

Organisers said they were expecting record numbers to attend

The relatives, some of whom campaign for the massacre to be commemorated as part of the Tiananmen Mothers group, told the BBC plain-clothes police were guarding the graveyard and they were told not to talk to the media.

Nobel Peace Prize-nominated rights activist Hu Jia, currently under house arrest, said he regretted not being able to take part in commemorations.

"But it warms my heart that those events and those sacrifices have not been forgotten after 25 years," he told the Associated Press.