Photos: 'Wall of Moms' face down federal officers in Portland

Wearing bike helmets and yellow T-shirts, America's mothers are confronting federal agents in combat gear to protect anti-racism protesters in Portland and, soon, other U.S. cities where President Donald Trump has vowed to crack down.

Mothers participate in a demonstration outside the Justice Center during a protest against racial inequality in Portland, Oregon, U.S.

Mothers protest against racial inequality and police violence in Portland.

Mothers protest against racial inequality and police violence in Portland.

Carrying signs like "Feds stay clear. Moms are here," and "I'm so disappointed in you - mom," the Oregon women have been shoved and tear-gassed by agents.

Mothers protest against racial inequality and police violence in Portland.

Carrying sunflowers, large peace symbol cut-outs and signs like "You need a time out," hundreds of mothers now link arms on the frontline of nightly protests at the city's federal courthouse, braving tear gas and other non-lethal munitions.

The Wall of Moms movement carries on a tradition of maternal activism, notably the Mothers of the Plaza de Mayo in Buenos Aires who held weekly vigils for nearly three decades to draw attention to the disappearance of their children under a military dictatorship.

Mothers protest against racial inequality and police violence in Portland.

Mothers protest against racial inequality and police violence in Portland.

Mothers dressed in yellow take part in a demonstration against the presence of federal law enforcement officers and racial inequality in Portland.

A woman holds a makeshift shield as she takes part in a demonstration against the presence of federal law enforcement officers and racial inequality in Portland.

Demonstrators attend a protest against racial inequality in Portland, Oregon.

Mothers stand between federal law enforcement officials and demonstrators during a protest against racial inequality in Portland.

Mothers raise their fists as they support a protest against racial inequality in Portland.