Balloons are perhaps not a frequent sight at protests, but the two clutched by Devon Fredericksen in the streets of Portland tell the story -- together, they read 57.

"I think it's crazy that it's been 57 days and we're still pushing for more change," Fredericksen told AFP. "How much longer is this going to take past 57?"

A demonstrator waves the US flag as several protesters manage to breach the fence at the federal courthouse in Portland
A demonstrator waves the US flag as several protesters manage to breach the fence at the federal courthouse in Portland AFP / Ankur Dholakia

The city, the biggest in the US state of Oregon, has seen nightly demonstrations against racism and police brutality for nearly two months, initially sparked by the death in Minneapolis of unarmed African American George Floyd.

It is also now the scene of a controversial crackdown by federal agents ordered by US President Donald Trump -- one that is not supported by local officials.

One protester in Portland carried a sign with a quote from a postwar confessional speech by German pastor Martin Niemoller -- "Then they came for me"
One protester in Portland carried a sign with a quote from a postwar confessional speech by German pastor Martin Niemoller -- "Then they came for me" AFP / Ankur Dholakia

Thursday's mainly peaceful demonstration ended like many before it -- in a showdown between protesters and police, which escalated in a haze of tear gas and flash bangs.

Clashes erupted by around midnight, though the two sides were separated by a protective fence reinforced by a barricade.

Protesters and police square off in Portland -- a nightly occurrence for nearly two months
Protesters and police square off in Portland -- a nightly occurrence for nearly two months AFP / Ankur Dholakia

Protesters targeted the federal courthouse, a flashpoint in the demonstrations -- hurling trash and launching fireworks over the fence. Blazes sprang up.

Federal agents wearing fatigues lobbed tear gas canisters back at demonstrators, used flash bangs and fired pepper balls, after declaring the gathering unlawful.

At about 1:30 am, law enforcement moved from behind the fence into the streets, advancing on protesters.

Demonstrators march to the federal courthouse in Portland -- to demonstrate against both racism in policing and the presence of federal law enforcements agents in the streets
Demonstrators march to the federal courthouse in Portland -- to demonstrate against both racism in policing and the presence of federal law enforcements agents in the streets AFP / Ankur Dholakia
Mothers form a human chain during a protest in Portland
Mothers form a human chain during a protest in Portland AFP / Ankur Dholakia

Though most demonstrators initially took to the streets after Floyd's death in late May to call for police accountability and reform, some say they now have different reasons.

On Thursday, the hundreds of protesters chanted "Black Lives Matter" -- but also "Feds go home."

The presence of federal agents in Portland has been roundly criticized by local officials, but President Donald Trump has vehemently defended their deployment
The presence of federal agents in Portland has been roundly criticized by local officials, but President Donald Trump has vehemently defended their deployment AFP / Ankur Dholakia

"I never thought that I would have to be out here in the streets of my city having to do this," said one demonstrator, who only gave his first name, Steve.

"It seems to me like it's one small step away from full-fledged military occupation of a free city that has every right to be here and to do this."

He carried a sign with a quote from a postwar confessional speech by German pastor Martin Niemoller -- "Then they came for me."

Tear gas fired during another night of protests in the US city of Portland
Tear gas fired during another night of protests in the US city of Portland AFPTV / Agnes BUN

Steve also said he came out Thursday because he supports the Black Lives Matter movement, and because Floyd's death should frighten people of all races.

"Black people have been struggling for an equal existence forever, so that's nothing new," he said.

"But the fact that it's been recorded and distributed... (it) is really starting to get through to more people now, how atrocious the situation is," he explained.

"I think it's a great thing that the message is getting out, but it had to happen in the most tragic way and the most terrifying way. Everyone should be terrified."

Protests in Portland directly linked to Floyd's death started to lose steam in early July.

But then reports emerged of federal officers taking demonstrators away in unmarked vehicles.

The city's Democratic mayor Ted Wheeler has accused federal officers of triggering a dangerous escalation of the situation with abusive and unconstitutional tactics.

As he met with protesters on Wednesday, Wheeler himself was hit by tear gas, an incident he described as "flat-out urban warfare."

Trump has now vowed to deploy federal agents in other cities such as Chicago to help tackle an uptick in gun violence. But local officials have warned they would draw the line at any Portland-style deployment.

"We're not going to allow the unconstitutional, state-sanctioned lawlessness we saw brought to Portland here in Chicago," Mayor Lori Lightfoot said on Twitter.

The US Justice Department's independent watchdog announced Thursday it was launching probes into the use of force by federal agents in Portland and in the US capital.

Teal Lindseth, one of the speakers at the Portland protest, said she is empowered by the movement's staying power in her city -- and is unbowed by the federal pressure.

"We're getting really big. Portland is being really seen."