PORTLAND, Ore. — From New York to Illinois to California, in red states as well as blue, protesters decrying Donald Trump’s election spent another night overtaking highways, smashing store windows, igniting fires and in at least one city, facing pepper spray and rubber projectiles from police trying to clear the streets.

The demonstrations stretched into a third straight night Thursday and came to a head in Portland, Oregon, where thousands marched and chanted, “We reject the president-elect!” while some lit firecrackers and sparked a dumpster blaze.

Officers began physically pushing back against the crowd that at times threw objects at them, making 26 arrests and using flash-bang devices and types of smoke or tear gas to force people to disperse.

Trump himself fired back, tweeting: “Just had a very open and successful presidential election. Now professional protesters, incited by the media, are protesting. Very unfair!”

In Portland, police termed the protest a riot after some 4,000 protesters surged into the downtown area. After giving several orders to leave, officers fired what appeared to be rubber projectiles. It was not immediately clear if anyone was hit.

The number of protesters dwindled by early Friday, and police ordered those still in the streets to disperse immediately or be “subject to arrest and the use of riot-control agents.”

In Denver, protesters briefly shut down a freeway near downtown. Police said demonstrators made their way onto Interstate 25, stopping traffic for about a half-hour.

Protesters also briefly shut down highways in Minneapolis and Los Angeles.

In downtown San Francisco, high school students called out “not my president” as they marched, holding signs urging a Trump eviction. They waved rainbow banners and Mexican flags, as bystanders in the heavily Democratic city gave them high-fives from the sidelines.

“As a white, queer person, we need unity with people of color, we need to stand up,” said Claire Bye, a 15-year-old sophomore at Academy High School. “I’m fighting for my rights as an LGBTQ person. I’m fighting for the rights of brown people, black people, Muslim people.”

In New York City and Chicago, large groups gathered outside Trump Tower. In New York, they chanted angry slogans and waved banners bearing anti-Trump messages. Police still stood guard Friday on Fifth Avenue.

“You got everything straight up and down the line,” demonstrator David Thomas said. “You got climate change, you got the Iran deal. You got gay rights, you got mass deportations. Just everything, straight up and down the line, the guy is wrong on every issue.”