Anarchists continued to smash storefront windows and bus stops, damage cars and spray graffiti. Police deployed stun grenades and rubber bullets around midnight.
The chaos has attracted national attention: The Associated Press has called Oregon the epicenter of anti-Trump protests.
Mayor-elect Ted Wheeler decried the property destruction this morning.
"Last night, what started as a peaceful protest ended in violence and vandalism," Wheeler said in a statement. "While this was caused by a small group of people among thousands, such a conclusion is unacceptable. None of us – protesters, business owners, or the community at large – can afford for this to happen again."
Wheeler added on Twitter that he believed the objective of the anarchists was to undermine the protest.
The group leading the protest, Portland's Resistance, wants to make it clear they don't condone the vandalism that occurred last night, and that they aren't affiliated with it.