With Wednesday’s 25th anniversary of China’s crackdown on pro-democracy student protesters fast approaching, authorities are trying to block foreign journalists from reporting about the event and detaining others who seek to commemorate it.

A Chinese Australian artist who created a large diorama of Tiananmen Square using 350 pounds of ground pork was detained by authorities in Beijing on Sunday night, prompting Amnesty International and the Australian Foreign Ministry to express concern. Guo Jian, 52, had not publicly displayed the work, but shared photos of it with the Financial Times newspaper.

At least 66 people have been detained in connection with the Tiananmen anniversary, Amnesty International said. The detentions have happened not just in Beijing but also in a variety of cities, including Wuhan and Guangzhou.

Meanwhile, the Foreign Correspondents Club of China issued a statement saying that a number of foreign journalists and their local staff have been summoned by Public Security officers to be given lectures dissuading them from reporting on the anniversary. Some of the journalists were warned of “serious consequences” should they disobey the authorities, the club said.

In one case, a team of French broadcast journalists was stopped by police as it was attempting to do man-on-the street interviews about the Tiananmen anniversary and interrogated at a police station for several hours.

According to the club’s report, when one of the reporters asked the officers why they were being detained, the officer said: “You were speaking about a sensitive topic. You know that the topic is sensitive and the government [doesn’t] want people to speak about it.”

When the reporter asked which Chinese law had been broken, the officer reportedly replied: “It’s not a matter of law. It’s a matter of culture. The culture is above the law.” The club did not name the French journalists or specify their outlet.

In another case, Xin Jian, a news assistant for Japanese newspaper Nikkei, was detained in Chongqing on suspicion of “picking quarrels” after the paper interviewed detained lawyer Pu Zhiqiang.

China has gone to great lengths for years to suppress any reference to the events of June 4, 1989, when the military crushed a student pro-democracy demonstration centered in Tiananmen Square, killing hundreds, if not thousands -- the exact numbers remain fuzzy.

William Nee, a researcher at Amnesty International, said: “The past few days have seen the Chinese authorities ratchet up the repression .… They have gone further when compared to past years, including the 20th anniversary, with more people criminally detained this time.”

Zheng Wang, a professor at Seton Hall University who has written about collective memory in China, said such vigilance by authorities has helped prevent any cohesive recollection of the events among the Chinese public beyond the official Communist Party line. Many people under 30 know little about the crackdown.

"People may have a strong collective memory of something that happened 100 years ago, or even longer, but this was 25 years ago and there’s no discussion,” he said. “Because there’s no discussion there’s no public narrative about it, so it’s kind of like there’s no memory of it, especially when we talk about collective memory."