The usually peaceful Occupy D.C. campaign made a confrontational turn on Sunday disrupting McPherson Square and disobeying authorities causing them to arrest many protestors, marking the first mass arrest of this group of demonstrators in Washington.

The disruption started off with a small dispute over a wooden shelter that demonstrators put up on Saturday, but the small dispute soon turned in a loud ruckus.

As reported in the Washington Post some protestors challenged police orders to abandon and take down the half built 15-foot-tall shed.

U.S. Park Police officers arrested 15 demonstrators during the day charging them with crossing a police line, said Sgt. David Schlosser, Park Police spokesman.

At the beginning of the night police moved in and arrested protesters who stayed inside the shed all throughout the day, charging 16 people with disobeying authority and one of them was also charged with resisting arrest, reported the Washington Post.

Around 8:35pm police removed six protestors that were clinging to the roof of the shed and they later dismantled it.

The Occupy D.C. movement following protests around the World occupied a public park in downtown D.C. and protests against the “99 percent” of what they think to be oppressed by the wealthy few, reported the Washington Post.

The movement didn’t draw much controversy till now, as authorities detained 31 protestors, the first large arrest of D.C. demonstrators.