As protests for racial justice in Portland have continued for more than 50 nights, striking new images and tactics have emerged – particularly in resistance to the federal law enforcement officers whose actions have earned the ire of Oregonians who want them to leave.

A group of women who call themselves the Wall of Moms has drawn national attention, clad in bike helmets and goggles. They link arms to form a protective barrier between law enforcement and Black Lives Matter protesters who took to the streets after the May 25 death of George Floyd at the hands of Minneapolis police.

In a recent moment captured on video, a large crowd of the yellow-garbed women sing as if a lullaby, “Hands up, please don’t shoot me.”

The Moms say they follow the directions of Black leaders, and that their driving vision is that “we moms would take some physical hits in hopes our Black and Brown kids, friends, neighbors, and loved ones will be spared some pain.”

In another video, also taken by freelance journalist Sergio Olmos, a protester uses a hockey stick to push back a canister of tear gas. Another uses a leaf blower to blow back the gas, a tactic used last year by protesters in Hong Kong.

State and local leaders have repeatedly called for the federal agents to leave the city, arguing that their presence has made an already tense environment worse.

“The federal police have their marching orders on how they’re going to do things,” Portland Police Association President Daryl Turner told NPR on Tuesday. “And that coordination was not made with Portland police.”

In response to both the federal actions in Portland and the implied threat by President Trump to deploy federal officers to other U.S. cities, more than a dozen U.S. mayors have sent an open letter to Attorney General William Barr and Acting Department of Homeland Security Secretary Chad Wolf.

The letter calls on the Department of Justice and DHS to withdraw the forces from American cities and halt plans to send any more.

“Deployment of federal forces in the streets of our communities has not been requested nor is it acceptable. While U.S. Marshals have had jurisdiction inside federal courthouses for decades, it is unacceptable and chilling that this administration has formed and deployed the U.S. Department of Homeland Security Rapid Deployment Unit and is sending federal authorities to conduct crowd control on city streets and detain individuals,” the mayors write.

They point to the federal officers’ use of less-lethal munitions against protesters that have caused serious injury and to the grabbing of people off the street and pulling them into unmarked vehicles. “These are tactics we expect from authoritarian regimes – not our democracy,” the mayors write.

On Tuesday, Wolf said, “Portland is unique,” arguing that local officials and police hadn’t done enough to control what he said was violence stemming from the nightly protests, and saying those protests increasingly threaten federal buildings downtown.

Asked about Trump’s threat to send federal officers into other cities, Wolf said reporters could “ask the White House.”

Oregon Gov. Kate Brown said the situation in Portland had been starting to calm before federal forces arrived.

“The harsh reality is, this is about scoring political points with [Trump’s] base,” Brown told PBS NewsHour on Monday. “This is about political theater. If they were really interested in problem-solving or in public safety, they would be willing to de-escalate and engage in dialogue.”

“Instead, they bring more troops to the streets,” she added. “They take peaceful protesters off into unmarked cars. And, unfortunately, last weekend, they almost killed a peaceful protester. This is absolutely outrageous. It is a violation of the principles on which this country was founded.”