A rioter threw an explosive device at a federal courthouse in Portland early July 28, causing a detonation that could be felt more than a block away.
Rioting in Portland has continued on a nightly basis since late May, with support from city and state officials.
"What the [expletive] was that?" one onlooker said.
The Department of Homeland Security (DHS) said the explosion was caused by a Molotov cocktail, one of several explosives rioters threw. The Portland Police Bureau in its summary of the night's events said that the device was a Molotov cocktail, or something similar.
"A person threw a Molotov cocktail, or similar destructive device, against the front door of the courthouse which burst into a fireball when it struck the building causing a report to be heard and felt more than a block away," the bureau said.
"The crowd activity continued as before," it added.
In the hours leading up to the explosion, hundreds of people wearing gas masks and helmets gathered outside the courthouse and resumed their ongoing bid to topple the fence. They brought signs, hockey sticks, golf clubs, umbrellas, leaf blowers, and fireworks. They hurled rocks, bottles, and other objects, like the explosive device, at the building, and started a fire inside the fence, adding wood, garbage, and other debris to stoke the flames.
Before authorities put up the barrier, rioters set fires to the courthouse. They ripped off plywood and smashed windows.
"The fence was put up just to create some space. The fence was put up so the peaceful protesters could focus on Black Lives Matter and racial justice," Assistant U.S. Attorney Craig Gabriel told reporters in a call on Saturday.
If DHS and the U.S. Marshal's Service see rioters stop trying to damage the courthouse, "then the officers will go home," Gabriel said, adding, "I think, not to be flippant about it, but I think it's that simple."
So far, rioters have not stopped.
After multiple warnings to disperse were ignored, federal officers used tear gas and other crowd control munitions to move the crowd away from the courthouse. Portland police officers were not involved.
The crowd dispersed around 1 a.m.
Two arrests were made by federal officers, one for assault of a federal officer and one for failure to comply with a lawful order.
DHS didn't respond to requests for comment.
The defendants are facing charges including assaulting officers, failing to obey lawful orders, and operating a drone in restricted airspace.
Since early July, 74 people have been arrested by federal officers, and 60 have been charged.
