BEIJING—Chinese authorities detained or interrogated more than a dozen labor activists in a southern manufacturing hub this week, a sweep that underscores Beijing’s growing anxiety over worker unrest.
The activists, mainly based in the cities of Guangzhou and Foshan, were rounded up by police for questioning Thursday, according to some of the activists and their associates. They said as many as 19 people were taken in, though a precise number wasn’t clear because those detained work for different groups.
Fellow activists and friends say those detained or interrogated are current and past staffers at four labor-rights nonprofits active in Guangdong province.
They said some activists were released Friday, but at least 10 people remained out of contact as of Saturday evening, including three activists who have been placed under criminal detention, which allows police to prepare for a formal arrest and possible prosecution.
Of the three under criminal detention, two were accused of “assembling crowds to disturb public order,” while the third person was accused of “duty encroachment,” which is defined as a form of embezzlement in Chinese law, according to their associates and copies of detention notices reviewed by The Wall Street Journal.
Phone calls to Guangdong police went unanswered Saturday, and efforts to contact police in Guangzhou and Foshan were also unsuccessful.
It wasn’t clear what prompted the sweep, though authorities in the Pearl River Delta region—a sprawling industrial slice of Guangdong that produces more than a quarter of China’s exports—have increasingly clamped down on industrial unrest that has swelled over the past year, amid an economic slowdown that has led to a rise in layoffs and wage disputes.
China Labour Bulletin, a Hong Kong-based watchdog, counted more than 2,300 strikes and labor protests on the mainland so far this year, far surpassing the 1,379 incidents recorded in the whole of 2014. In November, the group counted 301 incidents in what it called a record monthly tally, including dozens of protests in Guangdong linked to unpaid wages and factory closures.
Most of the detained activists couldn’t be reached for comment, and it wasn’t clear if they had legal representation. However, one of them, Chen Huihai, said in a brief phone interview that he was being held under police supervision in Guangzhou’s Nansha district, pending further investigations.
“It’s not convenient for me to speak now,” said Mr. Chen, who heads his own nonprofit that assists workers involved in labor disputes. He said he knew some of his fellow activists had also been detained, but wasn’t aware of the details.
Scholars say the crackdown appeared to target activists who focus on organizing workers involved in labor disputes and advising them on how to collectively negotiate over unpaid wages and other grievances.
Collective bargaining—the process of negotiating terms of employment between employers and organized groups of workers—is a touchy subject in China, where state-controlled unions are the only legal form of organized labor tasked with negotiating on behalf of workers. The practice has increasingly featured in industrial disputes in Guangdong, as workers and activists try to circumvent the government-backed trade unions, which many workers say they don’t represent their interests.
“The authorities are worried about efforts to organize workers beyond their ambit of control,” said a Beijing-based academic affiliated with China’s official trade-union federation, who declined to be named for fear of retaliation. “They are drawing a line in the sand, to warn activists and workers against stirring trouble.”
One of the activists under criminal detention is Zeng Feiyang, founder of the Guangdong Panyu Migrant Workers Center, which has been assisting workers in collective negotiations, including in a recent dispute between sanitation workers and their employment agency. Mr. Zeng, 40 years old, couldn’t be reached for comment and his mobile phone has been switched off since Thursday.
“This is a very sensitive time to be engaging in collective bargaining,” said Chen Weiguang, a retired unionist and former chairman of Guangzhou’s official trade-union federation. “Some labor NGOs have been perceived as adopting radical tactics in organizing workers, which may be harmful to social stability, particularly in the context of a slowing economy.”
In March, top Communist Party and government officials called for greater efforts to foster labor harmony, signaling Beijing’s growing concern that festering industrial tensions could soon threaten social stability or even weaken the Communist Party’s grip on power.
Local officials meanwhile have adopted increasingly aggressive tactics against unrest, arresting activists and workers, as well as deploying riot-control police to break up strikes. They have also forced some labor nonprofits to regularly relocate their offices in a bid to disrupt their work, activists say.
—Fanfan Wang in Shanghai contributed to this article.
Write to Chun Han Wong at firstname.lastname@example.org