In contrast, the state troopers did not intervene even when the scale of the protest on Thursday night passed the point, as demonstrators shook the fence around the courthouse, at which in early demonstrations the federal agents generally fired tear gas, stun grenades and baton rounds.

In the absence of confrontation, and with the state police remaining largely unseen inside the courthouse, tensions quickly eased. Without the federal forces to draw attention, protest organisers kept the focus on Black Lives Matters and reform of the Portland police.

Some in the crowd worked to avoid trouble by stopping demonstrators from lighting fires and shooting fireworks at the courthouse as they had done on previous nights.

Dan Thomas, an African American man, stood in the street shouting at people not to cause a confrontation with the state police.

“Attacking the federal building is not Black Lives Matter. Leave it alone. You’re playing into Trump’s hands,” he said.