China has been violently trying to suppress on a new target: A vocal group of student communists campaigning for workers' rights.

Student activists fighting for labor rights around the country have been beaten up and detained. Witnesses have also been attacked.

The Chinese Communist Party's crackdown on the student group, who describe themselves as Marxists and Maoists, appears counterintuitive.

But China has long opposed of all kinds of grassroots protests for the sake of maintaining the country's stability.

China's Communist Party is cracking down on a new target — student communists campaigning for workers' rights.

At least a dozen student activists campaigning for workers' rights in China are missing, their friends have told outlets including Reuters, The New York Times, and The Guardian.

Over the past week agents of the Chinese government violently rounded up the young activists in major cities including Beijing, Guangzhou, Shanghai, Shenzhen, and Wuhan, and detained them. Their whereabouts remain unknown.

Their friends and associates told Reuters this was likely a coordinated effort to silence their campaign.

The student activists have been demonstrating in support for workers' rights in China. Their campaign started this summer when they protested against factory workers who were fired and arrested for trying to form a labor union. Here is one of the protests in August. Sue-Lin Wong/Reuters

More than ten people wearing dark clothing beat and dragged one activist, Zhang Shengye, into a black car last Friday night, Agence France-Presse reported, citing Zhang's associates.

Zhang, a recent graduate of the prestigious Peking University, was taken from the school's campus. His associates alleged that the university "acquiesced to the kidnapping," according to Agence France-Presse.

Other students passing by were also beaten up and stopped from taking photos or speaking, Agence France-Presse reported.

22-year-old witness Yu Tianfu, who was studying in a nearby cafe, told The New York Times agents threw him to the ground, covered his mouth, kicked his head, and threatened to attack him more if he shouted again.

At least four other Peking University students and alumni were rounded up that day, Reuters reported.

Read more: Here's what China does to people who speak out against them

Peking University's campus in Beijing, China, where at least five student activists were beaten up and detained by unknown Chinese agents. kenner116/Wikimedia Commons

Why is the Communist Party cracking down on communists?

The missing activists formed part of a vocal group of campaigners who have since this summer staged protests around the country to support workers' rights.

The student activists describe themselves as Marxists and Maoists, and say their support of workers' rights were part of their communist agenda, The Guardian reported.

They originally formed their campaign to support workers at Jasic Technology, a welding machinery company in Shenzhen, who were fired and arrested for trying to form a labor union.

But their protests have since expanded to other causes, including alleged worker abuse at an unnamed Chinese supplier for Apple, and for miners suffering from lung disease, The New York Times reported.

But this new crackdown by the Chinese Communist Party — formed decades ago to reflect Marxist theory and to support land workers' rights, and who still requires universities to give lessons on Marxism — is not as surprising as it sounds.

The Chinese state today, keen to maintain one-party order, disapproves of all kinds of grassroots protests as they are seen to undermine the party and disrupt the country's stability. Additionally, while China's communist party retains the central government and economic planning of Marxist governments, it's widely embraced capitalism and private enterprise.

This opposition to grassroots organizations extends to labor activists and independent unions.

Student activists pictured in an apartment on Thursday, August 23. Police burst into this apartment on Friday, and the students' whereabouts are not known. Sue-Lin Wong/Reuters

In August Chinese riot police detained at least 40 of those student activists who were planning a demonstration for Jasic workers in Shenzhen.

Video footage showed riot police, wearing helmets and carrying shields, bursting into the students' apartment and scuffling with them.

Some of those students remain missing, the Financial Times reported.