CHICAGO (CBS) — Anti-police protesters are demonstrating to mark 500 days since a police officer killed Laquan McDonald.

CBS 2’s Derrick Blakley reports demonstrators gathered outside the George Dunne Cook County Building Wednesday afternoon, protesting State’s Attorney Anita Alvarez in her role for her role in police shootings.

The small demonstration of less than 50 people has caused plenty of commotion in the Loop.

It began as a rally at State and Jackson and then protesters went on the move. The biggest and most prolonged confrontation came on Adams just west of Michigan Avenue, not far from the Art Institute, when several protesters were arrested for blocking the street and the flow of traffic.

Police endured a barrage of insults until calm was restored and the marchers eventually returned to Jackson and State before moving again.

Earlier Wednesday, relatives of those killed by Chicago Police officers held a peaceful demonstration in the Thompson Center.