ST. PAUL — Groups of demonstrators overran the 3rd Police Precinct building in Minneapolis late Thursday night and congregated on the spot cheering and setting off fireworks as the building was set ablaze.

Minneapolis Mayor Jacob Frey told reporters early Friday that he'd given the order to have officers evacuate the building. No officers were seriously injured in the event.

Across Minneapolis and St. Paul, looting continued overnight and arson fires were set in hundreds of storefronts in protest of the death of George Floyd on Monday while in custody of the Minneapolis Police Department. Fires continued to burn Friday morning and business owners and residents again came out to survey the damage and begin picking up the pieces.

In St. Paul alone, more than 170 buildings were damaged or looted, according to the official city police Twitter account. Dozens of fires were reported as well as one gun homicide that is still being investigated.

Adding to the tension was a late-night tweet from President Donald Trump, who appeared to threaten further National Guard action Thursday. "Any difficulty and we will assume control but, when the looting starts, the shooting starts," the president tweeted.

Gov. Tim Walz and Department of Public Safety Commissioner John Harrington on Friday morning were set to speak with reporters about the protests and damage from demonstrators.

Walz on Thursday called in the Minnesota National Guard, which dispatched more than 500 troops to assist the Minneapolis State Patrol, St. Paul police and other squads activated to monitor the protests.

Walz was also expected to comment on the arrest of three CNN reporters who were apprehended at the scene of the Minneapolis protests while live broadcasting. They identified themselves as journalists but were arrested anyway. The State Patrol in a tweet said they were released after they were confirmed to be reporters, but the reporters themselves and CNN said the journalists made clear throughout the incident that they were working press. Walz apologized to CNN for the incident Friday and helped get the three released.