Figures released by the Portland Police Bureau showed fires were lit by protesters on 41 of the 83 nights of protest, acts of vandalism were committed on 49 nights, and projectiles were thrown during at least 58 nights.
Since the protests began on May 29, police have only recorded seven nights that were free of vandalism, fireworks or intentional fires.
The unrest was sparked by the death of Mr Floyd by police in Minneapolis.
In a statement, officers in Portland said: “When criminal behaviour occurs, especially behaviour threatening the safety of those near the event or those targeted by the event, law enforcement must respond.”
For weeks, police officials have received questions regarding where demonstrations have been taking place in the city, crimes that occur and police actions.
The department released a timeline of the protests in response.
The most recent data was from Wednesday night, when police said two people were arrested and protesters lit fires, committed vandalism and threw projectiles.
Individuals Throw Softball Sized Rocks at Officers, Light Fires, Break Windows, and Vandalize Building during Mass Gathering at ICE Building (Photo) https://t.co/52rQhgBfbb pic.twitter.com/unDnioQdJf
— Portland Police (@PortlandPolice) August 20, 2020
Police declared a riot, meaning six or more persons are engaging in “tumultuous and violent” conduct and intentionally or recklessly created a grave risk of public alarm.
Protesters clashed with federal agents for the first time in weeks at a demonstration targeting a US Immigration and Customs Enforcement building.
Windows were spray painted and broken before a riot was declared and authorities used tear gas and other riot control methods to break up the crowd, The Oregonian reported.
Several officers suffered minor injuries after they were hit with rocks.
