SHANGHAI — Chinese media have launched a strongly worded attack on seven labor activists detained earlier this month in southern Guangdong province, in what observers say is a sign of official anxiety at a growing number of strikes in the region, amid a slowdown in China’s economic growth rate.

A long article by the official Xinhua News Agency, published in many Chinese newspapers Wednesday, denounced the activists — most of them linked Panyu Migrant Worker Center in the provincial capital Guangzhou, as an "illegal group." It accused them of “receiving funding from foreigners, interfering in labor disputes … [and] trampling roughshod on the rights of workers." And it said they had "severely disturbed social order." Human rights groups, however, have said the attack is part of an official smear campaign, and risks undermining the legal process.

The Panyu Migrant Worker Center is one of China’s most active and outspoken groups campaigning on behalf of workers, in a country that only has one official trade union, affiliated to the government. However, China’s leadership has become increasingly intolerant of civil society organizations in recent years, according to activists, and the center’s staff have previously complained of official harassment. But Geoffrey Crothall, spokesman for Hong Kong-based monitoring group China Labor Bulletin (CLB), told International Business Times that the current crackdown represents “an escalation of the level of intimidation.” One of those detained, Zhu Xiaomei, is mother of a 1-year-old daughter, according to CLB.

The article reserved much of its vitriol for the center’s director Zeng Feiyang, who it said saw himself as “the star of the worker’s movement.”

“What kind of a man is Zeng Feiyang? ... What kind of serious crimes are [the activists] suspected of?” it asked, before criticizing Zeng’s private life and personal relationships. It accused Zeng and others of stirring up tensions between workers and factory managers, encouraging workers to make unreasonable demands and use “extreme methods,” and trying to derail negotiations for their own ends. It gave the example of a protest by workers from the Lide Shoe Factory earlier this year, where the Panyu activists helped workers laid off when the factory moved, to gain compensation. The article quoted workers as saying they regretted getting involved with Zeng’s organization.

It also attacked Zeng for sending photographs of labor disputes to foreign media, and giving interviews in which he revealed “negative information.” Foreign media, it said, exaggerated the tensions between workers and employers, and distorted the issue into "a conflict between workers and the Chinese government ... in an attempt to blacken China’s image and attack the country’s social system."

Human rights groups say the crackdown on labor activists is part of a deepening campaign to reduce the influence of outspoken critics and civil rights activists at a time when the Chinese authorities are concerned about social order, particularly as the economy slows. Guangdong, one of China’s biggest manufacturing regions, saw more than 300 strikes and disputes in the first eleven months of 2015, according to CLB, with the number reaching a record 56 in November alone. Some were over unpaid wages or benefits, others caused by factories suddenly closing or laying off workers, as parts of the region have been hit by falling export and domestic demand. 

 Xinhua also said seven other activists from a worker’s center in the nearby town of Foshan had been detained and placed under investigation. 

Observers said that the public denunciation of the activists, apparently before they have been formally charged or sent for trial, follows a pattern the Chinese authorities have used in the past two years: A number of bloggers, legal activists and journalists seen by the government as a threat have been detained and singled out for criticism in the media, or in some cases paraded on national television to confess to wrongdoing. Some critics have said this approach is alarmingly reminiscent of the tactics of public denunciation used during China’s "Cultural Revolution" in the 1960s and 70s.

Patrick Poon, a China researcher at Amnesty International, described Xinhua's attack on the activists as part of a “smear campaign.”

“Putting these people on a ‘public trial’ by the national media instead of following formal procedures deprives them of any chance to have a fair trial,” Poon told Hong Kong’s South China Morning Post.

CLB also said Zeng Feiyang had recently been denied access to his lawyer, who was told that he could not see his client because the case involved "state secrets." CLB's Geoffrey Crothall said the tough line “will almost certainly make labor tensions worse … as more factories close down and workers demand proper compensation.”

Activists say Chinese migrant workers have become increasingly aware of their rights, partly as a result of the work of groups like the Panyu Migrant Worker Center, and are often better educated than those who fueled China’s initial manufacturing boom two decades ago — and are therefore keen to be taught how to get better terms from their employers. However, some factory owners have complained that this has led to a rise in the cost of manufacturing in China, adding to the pressures on business.

And the Chinese authorities appear to be increasingly determined to take a tough line against various forms of civil society activism. On Tuesday, a court in Beijing handed one of China’s most famous civil rights lawyers, Pu Zhiqiang, a three-year jail sentence for “provoking trouble" by writing social media posts criticizing official policy. Although his jail term was suspended, rights groups said that having a criminal record would prevent him from working in China again.

The government has also drafted a new NGO law that seeks to tighten rules on such groups, and would further restrict their access to foreign organizations and funding. The Chinese government has increasingly warned of the dangers of “hostile foreign forces” seeking to influence and change China’s political system by means of NGO links and engagement with Chinese civil society.