Three far-right followers have been arrested at Las Vegas protests over the killing of George Floyd, an unarmed Black man, by police and charged with inciting violence.
The plot was reportedly foiled with help from an informant.
Stephen Parshall, 35, Andrew Lynam, 23, and William Loomis, 40, who allegedly belong to the “boogaloo” movement, all live in Las Vegas where they were arrested on Saturday by an anti-terrorism unit headed by the Federal Bureau of Investigation (FBI).
They were in possession of Molotov cocktails when detained, prosecutor Nicholas Trutanich said.
If convicted on federal charges, the men face up to 30 years in prison. They were also indicted on state conspiracy to commit terrorism and other charges, which carry heavier sentences.
The “boogaloo” movement, which has adopted Hawaiian shirts as a uniform, promotes “a coming civil war and/or collapse of society”, said the Nevada US Attorney’s Office on Wednesday.
“Violent instigators have hijacked peaceful protests and demonstrations across the country, including Nevada, exploiting the real and legitimate outrage over Mr Floyd’s death for their own radical agendas,” Trutanich said.
Reports of far-right activists, sometimes heavily armed, infiltrating the protests over the past week have included several claiming to be part of the “boogaloo” movement.
Members were seen at demonstrations in states including Minnesota and Texas, as well as in the city of Philadelphia, NBC News reported.
A charge sheet said the three men’s initial plan was to “firebomb” a power station to distract authorities as they incited a riot. They also intended to take Molotov cocktails to a Black Lives Matter protest.
“They wanted to use the momentum of the George Floyd death … to hopefully stir enough confusion and excitement, that others see the two explosions and police presence and begin to riot in the streets out of anger,” it said.
According to a report by the Network Contagion Research Institute, the group wants a second civil war organised around the word “boogaloo”.
The US has been roiled by nationwide protests over the killing of Floyd by a white police officer in Minneapolis on May 25.
The demonstrations have been largely peaceful, but many have broken down into violence and looting after nightfall.
Police and other law enforcement agencies have come under heavy criticism for the way they have responded to the protests. Thousands have been arrested and many injured.
Law enforcement agencies have defended the crackdown, saying they are responding to violent demonstrators involved in looting, vandalism, and fires that have broken out.
US President Donald Trump has threatened to invoke the Insurrection Act to use active-duty troops to disperse the protests, drawing criticism from across the political spectrum.
Trump’s former secretary of defence, James Mattis, slammed the president on Wednesday for trying to sow division, accusing him of setting up a “false conflict” between the military and civilians.
The current defence chief, Mark Esper, has also said he opposed Trump’s threat to send in the military to quell the unrest.