BEIJING >> “I’m sorry, I cannot be interviewed,” said Ding Zilin, a founder of Tiananmen Mothers, a group of families of democracy protesters killed by the Chinese military in 1989. She spoke Wednesday, three days before the anniversary of her son’s death.

Sounding frail, Ding, a 79-year-old former philosophy professor, did not detail why she could not be interviewed. But before hanging up she added, “There are people watching and checking at my door.” Each year, the authorities guard Ding’s home in Beijing’s university district, turning away journalists and other visitors.

Reports circulating in Chinese and English on social media said that her telephone line had been cut and that the Public Security Bureau had issued her a special mobile phone with only three contact numbers, including China’s emergency medical care number, 120. Ding picked up her home landline Wednesday morning, although she hung up before she could be asked about a special phone or other details. She was also receiving text messages on her mobile phone, said You Weijin, a fellow member of the Tiananmen Mothers.

Nearly three decades have passed since Jiang Jielian, then 17, the son of Ding and her husband, Jiang Peikun, was killed on the night of June 3-4, 1989. He was one of hundreds, perhaps thousands, who died in the suppression of the democracy protests that convulsed the capital for weeks.

They have been years of “white terror and suffocation,” the group’s 131 surviving members said in a statement issued Wednesday. This year, it highlighted the police harassment they face and once again called for justice for the victims.

The government has never apologized for the killings or revised its judgment that the protests in Tiananmen Square were a “counterrevolutionary rebellion.”

Here are excerpts from the statement, as translated by Human Rights in China:

“Twenty-seven years have passed since the June Fourth Massacre of 1989. For us, family members of the victims’ families, it has been 27 years of white terror and suffocation.

“For 27 years, the police have been the ones who have dealt with us. For 27 years, they have also been our frequent visitors at home. Each beginning of the year, from the anniversary of the late premier Mr. Zhao Ziyang’s death, to the Two Congresses, Tomb Sweeping Day, anniversary of June Fourth, to major national events and foreign politicians’ visits — we the victims’ families are eavesdropped and surveilled upon by the police; we are followed or even detained, and our computers searched and confiscated. The police use contemptible means such as making up stories, fabricating facts, issuing threats, etc., against us.

“For 27 years, we, victims’ families, have rationally maintained our three appeals: truth, accountability and compensation, in an effort to seek a just resolution to the miscarriage of justice of June Fourth. But 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.”

This year may be triply painful for Ding. Her husband died in September, and her daughter in December, of cancer, at the age of 49 or 50, according to You of the Tiananmen Mothers. Ding has a second son, believed to be in his 50s.

You said her own husband, Yang Minghu, then 42, was shot by soldiers June 4 and died two days later in Tongren Hospital. She said the police recently told her that anyone wanting to visit Ding around politically delicate dates such as June 4 needed to obtain permission. That drove the group to prominently feature police harassment in their statement, she said.

“Which law restricts us from visiting an elderly person?” asked You, 63.

As family members, often parents, of the victims die, their names are added to the growing list of deceased members. This year the number has risen to 41, up from 33 in 2013.

The Chinese government is playing “a waiting game,” said Albert Ho, the chairman of the Hong Kong Alliance in Support of Patriotic Democratic Movements in China, which will hold its annual June 4 memorial Saturday in the semiautonomous Chinese city of Hong Kong.

“They want it to drag on as long as possible, and they hope that, due to the passage of time and the dying of the family members, everyone will forget,” said Ho, who is also a Hong Kong lawmaker from the Democratic Party.

“But there is always in existence the collective memory of the people living in Beijing,” Ho continued. “There were so many eyewitnesses. Even if the victims’ families die, there are so many others in a position to testify in due course,” he said.

The Tiananmen Mothers have called for an independent investigation.

A U.S.-based human rights group, Duihua, says the last known person still in prison for taking part in the movement, Miao Deshun, is due to be released in October.

But Chinese Human Rights Defenders, another rights group, said scores of people who took part in the protests were in prison for their continuing advocacy of human rights and democracy.

© 2016 The New York Times Company