Stelsone/iStockBy JULIA JACOBO, ABC News(PORTLAND, Ore.) — A demonstration in Portland, Oregon, that included people breaking windows and taking down statues of former Presidents Theodore Roosevelt and Abraham Lincoln has been declared a riot by police.The protests were part of a “Day of Rage” declared over the celebration of Columbus Day on Monday.A mass gathering formed Sunday night in downtown Portland, where demonstrators used chains to topple the statues, the Portland Police Department tweeted just before midnight.The statues were erected in the 1920s, and several other statues that were considered possible targets were removed, The Oregonian reported. A statue of Thomas Jefferson was pulled down by protesters in June.About 200 people were in the crowd, according to the local newspaper.A glass window for the Oregon Historical Society was smashed with a police officer standing inside, ABC Portland affiliate KATU-TV reported. Police warned that anyone taking part in the vandalism was subject to a citation or arrest. About an hour after their initial tweet, Portland police declared the protests a riot and instructed all those marching to disperse or else crowd control measures such as tear gas and impact weapons would be used.The city has been experiencing months of unrest following the May 25 death of George Floyd, who died as a Minneapolis police officer kneeled on his neck for several minutes as three other officers watched on.In July, President Donald Trump’s administration deployed federal law enforcement to Portland, sparking tension between federal and local authorities and a public feud on Twitter between Portland’s mayor and a top homeland security official.Trump, who has put “law and order” at the forefront of his campaign for re-election, tweeted, “Put these animals in jail, now” Monday morning and criticized “The Radical Left fools in Portland” for not wanting “any real help.”Copyright © 2020, ABC Audio. All rights reserved.