Chinese authorities convicted four rights activists on charges of state subversion, who were detained last year as part of a nationwide crackdown on lawyers and activists.

House church leaders Hu Shigen and Gou Hongguo, human rights advocate Zhai Yanmin, and human rights lawyer Zhou Shifeng were put on trial at Tianjin Intermediate People's Court.

China had taken about 300 lawyers and activists in custody for questioning or detainment since July 2015.

Hu, 61-year-old church elder was sentenced to about seven years of imprisonment, while 55-year-old Gou was given a three-year suspended sentence, according to China Aid.

Zhai received a three-year suspension sentence while Zhou was sentenced to seven years in prison.

The Chinese state media Xinhua said that Hu was "engaged in state power subversion since the 1990s."

"Hu masterminded, spreading subversive ideas and plans and training agents such as Gou; Zhou ran the law firm as a front to carry out subversive activities with Hu and others; and Zhai, the "enforcer," who was instructed by Hu to organize paid petitioners for illegal protests, according to the statements," the agency stated.

"Not a single person defended themselves - they all pleaded guilty to the prosecution's charges, and they actively named other partners and conspirators. And in their final statements, all used the nicest terms to thank the prosecutor, the collegiate panel, the party, and said that they would never appeal," said a joint statement signed by human rights lawyers from Hong Kong and Taiwan.

The Chinese state media elaborated the concept of 'color revolution,' citing a legislator from Tianjin Municipal People's Congress, who said that "in essence a malign political attempt by some Western countries or interest groups to instigate domestic conflicts and collude with the country's insurgent forces to intervene in its domestic affairs, cause chaos, subvert state power and sway international political landscape and then reap benefits."

The U.S. State Department condemned the rulings by Chinese court, saying that these were "vague and apparently politically motivated."

"It's troubling that Chinese authorities denied these defendants access to their chosen counsel and family members as well," State Department spokesperson Mark Turner said. "We urge China to release all the lawyers and activists who were detained on 9 July 2015, and remove restrictions on their freedom of movement and professional activities."

The European Union also urged the Chinese government to drop the charges against the activists.

"The EU calls for the immediate release of those who have just been sentenced and the reinstatement of their right to practice their profession. All charges still pending against the other lawyers and human rights defenders detained since July 2015 should be dropped. China should allow trial observation by foreign diplomats," the EU said in a statement.