The Latest on May Day events across the United States (all times local):
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Seattle police say five people were arrested in May Day protests downtown.
Seattle police tweeted Monday night that those arrested ranged in age from 19 to 51. A 26-year-old man was arrested after reportedly throwing a rock as a group of Trump supporters met up with other protesters in Westlake Park.
Police Chief Ronnie Roberts in Olympia, Washington, said Monday night that nine people were arrested in a May Day protest-turned-riot and that all were booked on a felony riot charge.
Roberts says rioters hit nine police officers with rocks or marbles flung out of slingshots but no one was seriously injured thanks to helmets and other gear.
Thousands of union members and activists were marching in the shadow of some of the biggest resorts on the Las Vegas Strip during a May Day event organized to push back against Trump administration policies.
The loud and colorful demonstration Monday on Las Vegas Boulevard drew stares from tourists from Chicago, Boston and California, and remained peaceful.
In Olympia, Washington, police ordered protesters to disperse, calling them "members of a mob" as some threw bottles, used pepper spray and fired rocks from slingshots at officers.
Seattle police have arrested one person during a May Day rally.
Seattle police said on Twitter that the suspect was arrested early Monday evening for reportedly throwing a rock as a group of Trump supporters met up with other May Day protesters in Westlake Park.
Meanwhile in Portland, "numerous people have been arrested" in a May Day rally and march turned riot because of anarchists, police said.
Reporters from multiple media outlets in Portland were tweeting photos of broken and cracked windows at businesses including Target and J. Crew as well as at Portland City Hall.
Portland, Oregon, police say officers have arrested at least three people during a downtown May Day rally and march that they say became a riot.
Police said on Twitter Monday that anarchists destroyed a police car, damaged numerous windows and property, started fires in the streets and attacked police.
Police were telling people to leave the area or risk arrest after canceling a permit obtained for the May Day event.
It wasn't immediately clear if anyone had been injured.
Police in Portland, Oregon, say the permit obtained for the May Day rally and march there was canceled as some marchers began throwing projectiles at officers.
Police said on Twitter that all participants were encouraged to leave the march as smoke bombs and other items continued to be thrown at police Monday afternoon.
Police say the permit was being canceled "due to numerous incidents of thrown projectiles, incendiary devices, and other unsafe conditions."
No injuries had been reported.
Portland was among many major cities where thousands of people were demonstrating, but it was among the only spots where there was unrest.
About 200 people in Portland, Oregon, including some families with children, joined many thousands of others across the country in pro-labor, pro-immigration and anti-President Donald Trump rallies on May Day.
In Portland, dancers in bright, feathered headdresses performed to the beat of drums on Monday afternoon.
Several dozen people dressed entirely in black and wearing black bandanas and ski masks on their faces stood around the fringes of the gathering holding signs that read "Radicals for Science!" and "No cuts! Tax the rich!" as police officers looked on.
Across the country in Providence, Rhode Island, about the same number of people gathered at Burnside Park before a two-hour protest that touched on deportation, profiling and wage theft. The group followed a flatbed truck that stopped for speeches and booing in front of the sites such as the Federal Courthouse and City Hall.
In Los Angeles, dozens of pro-Trump protesters stood across from a large crowd of May Day marchers, waving American flags and blasting patriotic songs. The group left before any clashes or trouble emerged between the two sides.
A march toward downtown Chicago on May Day is taking up several city blocks, with organizers estimating an attendance of 20,000 people.
One of the participants is artist Brian Holmes, who says Monday's demonstration is the latest step in fighting policies issued by President Donald Trump. Holmes says he has participated in several marches, including a rally Saturday to protest Trump's agenda in rolling back environmental protections.
Many signs in the crowd call for an end to deportations. But advocates of several organizations are pushing for numerous causes, including workers' rights, environmental justice and a higher minimum wage.
A handful of Trump supporters wearing baseball caps with his campaign slogan "Make America Great Again" are in attendance.
Activists and immigrant advocates are marking May Day with another day of action in the Phoenix area after a weekend of marches and rallies that called for support of immigration and labor rights.
Organizers for Promise Arizona met with legislators at Arizona's capitol Monday to deliver postcards with messages of hope regarding International Workers' Day.
The group will hold a phone bank event later Monday to urge legislators and members of Congress to support immigrant families.
Immigrant advocates say the events will bring attention to President Donald Trump's crackdown on immigration during his first 100 days in office.
David Ayala-Zamora is the state field director for Promise Arizona. He says Trump is "terrorizing our communities" through his immigration policies.
Crowds have gathered in a park on Chicago's West Side to call for immigrant and workers' rights on May Day.
Among them is 28-year-old Brenda Burciaga, a U.S. citizen whose mother is set to be deported to Mexico soon.
She says her mother has lived and worked in the U.S. for about two decades. Burciaga says no matter what, immigrants deserve respect from President Donald Trump's administration.
Activists from labor groups, anti-police brutality organizations and groups seeking a higher minimum wage rallied Monday before a march downtown.
The atmosphere was festive, with local rappers riffing about peace, drummers warming up the crowd and labor advocates giving speeches.
Several area businesses with immigrant ties closed for the day or allowed employees to participate without being penalized.
The park rally followed demonstrations citywide.
Police in California say they have arrested four activists who chained themselves together to block the entrance to the county administration building in downtown Oakland on May Day.
Police are threatening more arrests Monday at the Alameda County Administration Building as more than 100 protesters demand an end to what they call collaboration between county law enforcement and the U.S. Immigration and Customs Enforcement.
Organizers want the county to become a sanctuary for immigrants, workers and people of color targeted by law enforcement policies under President Donald Trump's administration.
The protesters are beating a drum and chanting, "The people united will never be defeated" in English and Spanish.
The group also wants an end to the Urban Shield SWAT training exercises and a stop to a planned expansion of the county jail system.
With chants of "We are here to stay!" immigrants and labor leaders are marking International Workers' Day with marches and rallies in the Boston area.
Some 200 people gathered in front of the Statehouse on Monday to call on state lawmakers and Republican Gov. Charlie Baker to designate Massachusetts a "sanctuary state." The proposal would restrict state and local law enforcement officers from cooperating with federal immigration enforcement efforts.
Democratic state Sen. Jamie Eldridge is the bill sponsor and said it wasn't enough for individual communities to become sanctuary cities because workers must cross city lines to get to and from jobs.
Activists plan to march later Monday to Chelsea City Hall for a rally.
May Day rallies are being held nationwide to oppose President Donald Trump's immigration policies.
At least 200 people are protesting in New York City's Washington Square Park ahead of a much larger demonstration to oppose President Donald Trump's immigration policies.
The crowd on Monday listened to various speakers and performers who are focused on workers and immigrants. They're carrying signs that say, "No person is illegal" and "We won't tolerate Trump's fascist policies."
Brenda Enriquez says she's participating in a protest for the first time because "Trump is threatening to kick us out." The 27-year-old Queens resident is originally from Bolivia and lived in the U.S. illegally.
A coalition of immigrant rights groups, labor and religious leaders has organized what they're calling a "massive" rally for 5 p.m. in Lower Manhattan.
Demonstrations are being held across the world to mark May Day.
Labor and immigrant rights groups along with some local elected officials are planning a march to the White House to oppose President Donald Trump's immigration policies.
Groups around the country have a variety of demonstrations planned to mark May Day on Monday. In Washington, a march is planned Monday afternoon from Dupont Circle to the White House.
Some businesses in the area were closed Monday in support of the effort.
Salvador Zelaya owns a commercial construction company with offices in Washington and Alexandria, Virginia, and says he's paying his workers to take a day off and attend the march to the White House. Zelaya says his 18 workers are spending the morning making banners.
About 1,000 Philadelphia school teachers are protesting as May Day demonstrations begin across the U.S.
The teachers began picketing Monday morning outside city schools, and rallies and marches are planned throughout the day. Many took sick days to protest. Supportive parents are picketing at some schools and are expected to march later.
The educators have been working nearly four years without a contract and nearly five without a pay raise. Schools are open and the district says it's working with principals and the company that provides substitute teachers to ensure there will be no disruptions in the classrooms.
Immigrants and union members will participate in a series of strikes, boycotts and marches on Monday to mark International Workers' Day and protest against President Donald Trump's policies.
Immigrant and union groups will march in cities across the United States to mark May Day and protest against President Donald Trump's efforts to boost deportations.
Tens of thousands of immigrants and their allies are expected to rally Monday in cities such as New York, Chicago, Seattle and Los Angeles. Demonstrations also are planned for dozens of smaller cities from Ft. Lauderdale, Florida, to Portland, Oregon.
In many places, activists are urging people to skip work, school and shopping to show the importance of immigrants in American communities.
Around the world, union members traditionally march on May 1 for workers' rights. The day has become a rallying point for immigrants in the U.S. since demonstrations were held in 2006 against a proposed immigration enforcement bill.