Chinese police have detained several activists while others were under surveillance Saturday on the anniversary of the bloody Tiananmen Square crackdown, rights groups said.

Six human rights activists, including the poet Liang Taiping, have been held by Beijing police since Thursday after holding a private ceremony commemorating "June 4", the date in 1989 of the brutal crushing of pro-democracy protests in Beijing, the Chinese NGO Weiquanwang said.

They were suspected of "provoking quarrels and fomenting unrest", said the group, which also reported another activist had "disappeared" in recent days in the capital.

Nearly three decades after the crackdown by the military, the communist regime continues to forbid any debate on the subject, mention of which is banned from textbooks and the media and censored on the Internet.

As in previous years, the "Tiananmen Mothers", an association of parents who lost children during the violence, were placed under heavy surveillance.
Zhang Xianling, whose 19-year-old son was killed in 1989, told AFP that when she went to a Beijing cemetery on Saturday with a dozen other parents to pay their respects at the graves of their children, they were surrounded by security forces.

"We have been under surveillance since last week... 30 (plainclothed policemen) were at the cemetery," said Zhang.

The Mothers of Tiananmen penned an open letter slamming the "27 years of white terror and suffocation" they have been subjected to by the authorities.

"We the victims' families are eavesdropped upon and surveilled by the police; we are followed or even detained, and our computers searched and confiscated," read the letter signed by the group's members and released the NGO Human Rights in China.

- "Massacre never happened" -

"The government has ignored us, pretending that the June Fourth Massacre that shocked the whole world never happened in China, and refusing to respond to our appeals, while our fellow countrymen gradually lose the memory of the event," the letter continued.

The letter also said that the group had been warned that all visits to the home of the group's founder Ding Zilin, who is now 79-years-old and in poor health, would be restricted from April 22 to June 4.

"Those who want to visit her must apply for permission and may visit her only after approval by the Beijing Public Security Bureau, and they may not be accompanied by other victims' family members," the letter read.

Ding was under increased surveillance at her home and the police had cut the household telephone line, Hong Kong-based media reported.
Calls to Ding's telephone number on Saturday were met with a recorded message: "The user you have contacted does not have the right to receive calls." 

Chen Guang, a soldier-turned-artist, has been visited multiple times by police and civil security agents during the weeks leading up to the anniversary, he told AFP.

At the time of the twenty-fifth anniversary of the crackdown in 2014, Chen was placed in detention for a month after he put on an artistic performance in memory of the victims of Tiananmen.

Source: AFP