May Day marchers battled police in Seattle and Oakland on Friday night, injuring three officers as peaceful demonstrations gave way to chaotic and violent scenes around the cities.

In Seattle, demonstrators threw wrenches, bricks and rocks at police in the city’s Capitol Hill neighborhood and riot police fought back with pepper spray, flashbang grenades and pepper-ball projectiles. Protesters, some dressed in black clothing and masks, left in their wake a trail of smashed windows, garbage fires, graffiti about anarchy and property damage.

“This is no longer demonstration management. This has turned into a riot,” said police captain Chris Fowler. The Seattle police department said it had arrested 16 people as of 11pm local time, and that they likely would face charges including assault and failure to disperse.

On the arrested protesters police found wrenches, wooden poles, a hammer, a battery as well as blades. One man had on his person “a soda bottle filled with green paint, a wrench, and a machete painted with the word ‘death’”, police said.

At one point a shirtless man climbed a park basketball hoop and refused to come down – eventually entangling himself in the hoop as he resisted police. Police said he “ended up hanging upside down for some time until firefighters arrived with a ladder”.

At least three officers were injured, respectively suffering a dislocated shoulder, a broken wrist, and burns. Protesters were also injured in the scuffles, social media shows.

Tonight we saw assaults on police officers and senseless property damage, which cannot be tolerated. Seattle Mayor Ed Murray

“Seattle celebrates free speech, the right to assemble and freedom of the press,” Mayor Ed Murray said in a statement. “People are raising their voices across the nation, working constructively to advance issues of racial equity and justice in our society.

“What erupted tonight is a very different story. Tonight we saw assaults on police officers and senseless property damage, which cannot be tolerated. Those who are violent will be arrested. We will work to disperse groups that are threatening the safety of our residents and businesses.”

Police chief Kathleen O’Toole said in a press conference she thought officers “were very professional about how they handled the situation” but that the department would review its use of force.

Residents helped pick up in the wake of the chaotic demonstrations, and organizers asked self-styled anarchists to leave their part of the march during the day. In preparation for the marches, Starbucks boarded up its new storefront in the city.

Protesters march down Pike Street in Seattle. Photograph: Toby Scott/Demotix/Corbis

Earlier in the day, about 1,000 people protested peacefully at a rally that united the causes of workers’ and immigrant rights with the Black Lives Matter movement, which arose from outrage of the police killings of unarmed black men around the country.

El Comite organizer Oscar Rosales told the Guardian he and other groups felt that “though on the surface these issues seem separate, they’re all interconnected because of the experience of people on the social and economic margins”.

Rosales’s protest went without incident during the day but was followed by violent demonstrations and vandalism in the evening, a pattern repeated in Oakland, California and Portland, Oregon.

In Oakland, protesters broke into a car dealership to break windows and set several cars alight, burning one out completely. They also smashed windows at banks and stores, cursing at police and shouting “Baltimore, we got your back”, in reference to the anti-police riots that erupted there last week.

Peaceful protesters mingled in the crowd as well, with signs reading “stop police terror” and “no justice, no peace”.

In Portland, a crowd of people flung rocks and chairs at police, who responded with pepper spray and tried to hem demonstrators in along the pre-arranged route of the demonstration. Officers threw flashbang grenades to try to disperse the crowd when it tried to march onto a major bridge.

About 200 people succeeded in blocking a bridge in downtown Austin, Texas, but were stopped by police from marching onto a freeway and halting traffic there. In Chicago, New York and Los Angeles, hundreds gathered to protest against police abuses, wage stagnation and immigration laws.

The streets where cars burned in Baltimore were relatively quiet on Friday night, after a day of surprise and celebration at the news that six police officers will face charges for the murder of Freddie Gray, a black man who died in police custody.