Of the 21 protesters arrested in July of last year in Utah for participating in a direct action aimed at stopping operations at the first tar sands mining operation in the United States, six have now been charged with ‘rioting’ by local prosecutors.

According to the Salt Lake Tribune, the six—Jesse J. Fruhwirth, Camila A. Ibanez, Damien T. Luzzo, Laura M. Gottesdiener, Daniel J. Gruppo and Victor E. Puertas— could face harsh punishments after being charged with interference with an arresting officer, a class-A misdemeanor punishable by up to a year in jail, and the crime of “rioting,” a third-degree felony punishable by up to five years in prison.

Fourteen others who were arrested at the protest were charged with the lesser count of criminal trespass, while one individual was charged with refusing to obey the command of a police officer.

Responding to the elevated charges of the six named, Utah Tar Sands Resistance, a group which helped organize the nonviolent protest, asked, “When did a peaceful sit-in become a felony riot?”

All of those charged are expected to enter pleas to the local district court later this week.

The July 2014 action, as Common Dreams reported at the time, involved roughly 80 climate justice activists who entered the construction site operated by the Calgary-based US Oils Sands corporation and unfurled a banner which read “You are trespassing on Ute land,” referring the project’s encroachment on native land, and “Respect Existence or Expect Resistance.” Later, some of the group locked themselves to equipment and others blocked a nearby road.