The President-elect met with Barack Obama for the first time since the election
Protesters have spent a second night voicing their opposition to US President-elect Donald Trump as he hit back, describing them as "professional protesters" who were "incited by the media".
Police declared a "riot" in Portland, Oregon, as an estimated 4,000 people marched through the northwestern city, some smashing shop windows, lighting firecrackers and reportedly carrying baseball bats.
A dumpster bin was also set on fire and several people were detained by police.
Parts of Interstate 5 and Interstate 84 were closed as a precaution.
In Chicago about 50 people demonstrated on Thursday, a day after thousands of people marched around the city's business district.
They received cheers from some but at least one person shouted that they should "shut up and accept democracy".
Protesters also blocked Interstate 94 in Minneapolis after marching from an anti-Trump gathering at the University of Minnesota.
There were other protests in Denver, and also in New York, where people gathered outside Trump Tower on Fifth Avenue; Philadelphia, where hundreds gathered near City Hall; and Baltimore where police say around 600 people brought traffic to a standstill.
Mr Trump tweeted: "Professional protesters, incited by the media, are protesting. Very unfair!"
Just had a very open and successful presidential election. Now professional protesters, incited by the media, are protesting. Very unfair!— Donald J. Trump (@realDonaldTrump) November 11, 2016
Meanwhile, following his first meeting with Barack Obama, Mr Trump is understood to be preparing to dismantle one of the current president's main policies - Obamacare.
The billionaire has said a number of times that he would scrap the scheme, adding that healthcare would be among his top priorities following his inauguration on 20 January.
He also told reporters that immigration would be his other priority early in his term.
Mr Trump has previously promised to build a wall between the US and Mexico to stop illegal immigration from the south.
He said: "We are going to move very strongly on immigration.
"We will move very strongly on healthcare ... And we're looking at jobs - big league jobs."
Mr Trump's words followed a 90-minute talk with Mr Obama which he described as wide-ranging and a "great honour".
Mr Obama said he was encouraged by Mr Trump's willingness to work with his team on the issues facing the country, adding it was important for all "to now come together".
The respectful tone of their post-meeting news conference was in contrast to the bitter exchanges that characterised the election campaign before Mr Trump ultimately defeated Hillary Clinton, who was backed by fellow Democrat Mr Obama.
The White House said later that while the two men did not resolve all their differences, the talks "might have been at least a little less awkward than some might have expected".