PORTLAND, Ore. (KOIN) — After a group of roughly 100 protesters gathered at a North Portland park on Monday night, a majority of the crowd marched to the Portland Police Association building — eventually setting a billboard on fire.

With what police called “support vehicles” in tow, the group marched from Arbor Lodge Park toward the PPA building around 10 p.m, blocking traffic the entire way.

Officers in the area on N. Lombard Street started to warn the crowd over a loudspeaker, stating, “This is the Portland Police Bureau. The streets in the area around the PPA are open to vehicular traffic. Please remain on the sidewalk and be courteous to your neighbors. Do not vandalize buildings.”

Following the warning announcement, some members in the group immediately started to spray paint the PPA building, according to police. Others stayed in the street, continuing to block traffic. Meanwhile, some individuals climbed on top of some nearby business’ roofs.

By 11:15 p.m., police say people had started a fire on the billboard next to the PPA office.

The fire ended up extinguishing itself. Although the attached advertisement was burned, the billboard structure seemed to be unharmed.

The police union headquarters building has been the frequent site of past protests. This spurred another round of warnings from police who said that anyone who engages in criminal activity could be arrested and subject to the use of force.

Ultimately, no arrests were made and the crowd dispersed on its own by about 12: 15 a.m. Police did not interact with the crowd aside from the loudspeaker warnings.