The Oregonian reported police said there were no injuries among the protesters or officers but protesters said they had heard there were some injuries.
After the protesters were moved out, city parks staff moved in to clean up debris, police told the Portland newspaper.
Police also formed a perimeter around the parks and closed off traffic in the vicinity. More than 300 officers from several jurisdictions took part in the operation.
In Oakland, Calif., Mayor Jean Quan indicated Sunday time was running out for the Occupy protesters camped out at 14th Street and Broadway, the Contra Costa Times reported. There are about 150 tents in the encampment.
Quan said the city would open its winter shelter for the homeless Monday, a day earlier than expected. The shelter can accommodate about 100 people.
University of California, Berkeley, students have called for a campus-wide strike Tuesday to protest the treatment of some Occupy protesters.
"It is now clear to most Oaklanders that because of the increased violence associated with the camp and the strain on our city's economy and resources, now is the time for the encampment to end," Quan said in a statement.
Occupy Oakland activists say they would ignore efforts to evict them from their protest camp.
The city administrator's second eviction notice issued Saturday for the Occupy Oakland camp to vacate Frank Ogawa Plaza went unheeded as activists rallied, marched, met, meditated and held teach-ins, the San Francisco Chronicle reported Sunday.
One camper was packed and ready for police to evict her.
"It's going to be a tragedy when they clear us out, but I can't tell the mayor what to do," said Terry Dotson, 54, a self-described homeless person who's lived at the camp since it appeared five weeks ago. "When it started it was beautiful, but then a lot of hatred came in."
There have been incidents of vandalism and violence in the past few weeks and a fatal shooting Thursday of a young man next to the protest site, the Chronicle said.
Meanwhile, business owners near the encampment say the fear of potential violence has kept customers away, the Chronicle said.
"We are very distressed by the broad impact the encampment has had on downtown," J.C. Wallace, president of the Downtown Oakland Association told the newspaper. "This is hurting people who can't afford to be hurt, primarily small-business owners. It definitely deters people from coming downtown; there are fewer customers and business is down.
Cities have been cracking down on the Occupy movement in other parts of the country, with arrests of protesters elevating the tension.
Denver police arrested 17 people Saturday evening as they forced protesters out of Civic Center Park and tore down illegal encampments, The Denver Post reported Sunday.
"This isn't safe and, it's not sanitary," Sonny Jackson, spokesman for the Denver Police Department, told the newspaper, pointing to a pile of blankets with food and a stream of liquid running underneath it.
Eighteen people were arrested and one received a citation Saturday evening as Salt Lake City police cleared an Occupy campsite near Pioneer Park, The Salt Lake Tribune reported Sunday.
The sweep was a non-violent affair, police and many protesters said.
"Once they figured out we weren't going to throw bricks and rocks and stuff, they were very nice about it," protester Allen Langdale said of the police.
Salt Lake City Police Chief Chris Burbank said police were surprised to see the deplorable conditions of the encampment, noting some tents were being used as bathrooms and drug paraphernalia was found.
"It was actually much worse than I had anticipated," he told the Tribune.