China has reportedly detained or threatened dozens of people as part of a “wave of persecution” targeting those seeking to commemorate the victims of the Tiananmen Square massacre.

Tuesday will be the 30th anniversary of the infamous crackdown, which saw the Chinese army kill hundreds, possibly thousands, of protesters taking part in student-led pro-democracy demonstrations in Beijing’s central square.

Discussion or even acknowledgement of the 1989 incident has for years been suppressed by Chinese authorities in an attempt to erase collective memory of the bloodshed.

Amnesty International accused Xi Jinping, the Chinese president, of using the “same tired political playbook” in “cruelly persecuting those seeking the truth about the tragedy”.

“The Chinese government must accept that no amount of suppression will ever erase the horror of the wholesale slaughter that took place in and around Tiananmen Square,” said Roseann Rife, East Asia research director of the charity.

Tiananmen Square massacre: Timeline of events Show all 12 1 /12 Tiananmen Square massacre: Timeline of events Tiananmen Square massacre: Timeline of events Man blocks tank A tank driving down a road nearby Tiananmen Square is blocked by an unidentified man on 5 June. The picture is seen around the globe as a protest against the previous days events, when tensions that had been building for months came to a head... Bettmann Archive via Getty Tiananmen Square massacre: Timeline of events Hu Yaobang dies - 15 April Former general secretary of the Communist Party Hu Yaobang dies aged 73 of a heart attack. He was a leading reformer of the Chinese system who the public saw to be unfairly removed from government. Citizens flock to Tiananmen Square to mourn him. Mourning soon turns to anger as they dwell on the state of China. AFP/Getty Tiananmen Square massacre: Timeline of events Protests spread - 17 April In the days after Hu's death, university students around China are organising. On 17 April, thousands of students march on Tiananmen Square to demand democracy and greater freedoms. AFP/Getty Tiananmen Square massacre: Timeline of events "We must a clear stand against disturbances" - 26 April So begins the editorial on the front page of the People's Daily, the Chinese state newspaper, on 26 April. The editorial goes on to attack the protesters as anti-party and anti-government. Protesters read a clear message that the government is against them and call for the editorial to be retracted. Tiananmen Square massacre: Timeline of events Protests spread further - 4 May Thousands more students in five cities across China join the protests. Head of the Communist Party Zhao Ziyang tells a meeting of bankers that the protests are sure to subside. Pictured are journalists from the China Daily newspaper showing support in Tiananmen Square. Protesters were calling for freedom of the press, among other rights common to democracies Reuters Tiananmen Square massacre: Timeline of events Hunger strikes begin - 13 May Hundreds of students begin hunger strikes, upping the stakes of the protests. Pictured: Paramedics remove a student protester who has been on hunger strike on 17 May 1989 AFP/Getty Tiananmen Square massacre: Timeline of events Zhao visits Tiananmen Square - 19 May Now doubting that the strikes will subside without intervention from the government, party head Zhao Ziyang visits Tiananmen Square and urges students to end the hunger strike. Chinese premier Li Peng briefly joins Zhao but leaves soon after arriving. Zhao was removed from office later in the day. AFP/Getty Tiananmen Square massacre: Timeline of events Martial law declared - 20 May Chinese premier Li Peng declares martial law. Soldiers move in on Tiananmen Square but many are held up by protesters. Soldiers are ordered not to fire on civilians. AFP/Getty Tiananmen Square massacre: Timeline of events Protests continue - 22 May to 1 June On 22 May, a military helicopter drops leaflets above Tiananmen Square that instruct protesters to leave immediately. Despite this, protests continue while the army withdraws. Reuters Tiananmen Square massacre: Timeline of events Soldiers move in to clear the square - 3 June On the evening of 3 June, soldiers advance with force. Protesters are warned that the troops have the right to use any methods necessary to clear the square. AFP/Getty Tiananmen Square massacre: Timeline of events Soldiers open fire - 4 June In the early hours of the morning, some troops begin to shoot dead protesters who defy their efforts to clear the square. Pictured: A man is covered in blood after the People's Liberation Army open fire on protesters in Tiananmen Square Getty Tiananmen Square massacre: Timeline of events Man blocks tank - 5 June A tank driving down a road nearby Tiananmen Square is blocked by an unidentified man. The picture is seen around the globe as a protest against the previous days events. Bettmann Archive via Getty

Chinese Human Rights Defenders (CHRD), a US-based group supporting activism in China, said a number of activists had been taken into custody to “silence any expression or thwart any action” this year.

The group said it had documented cases involving 13 people who had been detained or “forced into disappearance”, including dissident writer Shen Liangqing, who was allegedly seized while walking his dog on charges of “picking quarrels”.

CHRD said Mr Shen was denied food, water and the use of a toilet for 24 hours.

On 28 May, six artists from Beijing went missing while on a “national conscience” tour, according to the wife of one of the men, Zhui Hun. Mr Zhui was also detained for “picking quarrels” and police confiscated his artwork, his wife said.

Authorities also reportedly put three activists on “forced travel” to prevent them from taking part in any demonstrations or from speaking out. One activist, Ou Biaofeng, has allegedly been removed to Guizhou and Yunnan provinces for at least two weeks accompanied by security officers.

Human Rights Watch said a number of “Tiananmen mothers” – women whose children were killed in the crackdown – had been restricted from travelling or placed under house arrest.

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Wang Yaqiu, a China researcher at Human Rights Watch, said the Chinese authorities still refuse to recognise the atrocities committed 30 years ago and had failed to compensate victims and their families.

“Concealing the truth of 4 June and strengthening the rule of high pressure throughout the country will only inspire the determination of human rights activists to pursue human rights and justice,” she said.