Three Chinese pro-democracy activists have been handed down up to five years of jail term Friday for “inciting subversion of state power,” human rights groups said. Tang Jingling, Wang Qingying and Yuan Xinting were arrested in May 2014 on charges of “creating disturbances,” which were upgraded to more serious charges in June 2014.

The Guangzhou Intermediate People’s Court’s indictment stated that Tang, Yuan and Wang “promoted the ideas of civil disobedience ... with the goal of overthrowing the socialist system,” according to Amnesty International. Prosecutors had cited publication of a series of books on civic activism, peaceful democratization and civil disobedience for charges against the activists. Tang, Yuan and Wang were given five, three-and-a-half years, and two-and-a-half years of prison sentences respectively.

“Today’s verdict against the three activists is a gross injustice. Their peaceful and legitimate work never threatened state security, this is solely about the authorities arbitrarily silencing government critics,” Patrick Poon, China researcher at Amnesty International, said Friday, in a statement.

According to Amnesty International and Human Rights Watch, police had beaten the activists in custody and their trials were marred with irregularities. The prosecution of the men is part of the Chinese government’s crackdown on activists that began shortly after President Xi Jinping formally assumed power in March 2013, the Human Rights Watch said. The government has randomly detained, arrested, forcibly disappeared hundreds of activists and limited freedom of expression in the country, according to the watchdog.

“The Chinese government needs to stop equating peaceful criticism with subversion if it is to make any progress towards respecting rights,” Sophie Richardson, China director of Human Rights Watch, said in a statement. “The prosecution of three rights activists on such dubious charges shows how far Beijing needs to go.”

Last August, the Communist nation also arrested Christian activists protesting the removal of crosses from churches. Activists have denounced the move, angering Chinese authorities who ordered plainclothes police officers to go to homes of the activists they intended to arrest. Since 2013, more than 1,200 crosses have been removed from churches, causing friction between China’s Communist Party and the church.