A night that started with a reported shooting and a bag containing loaded rifle magazines and Molotov cocktails amid a peaceful protest — morphed into an intense early morning confrontation between demonstrators and law enforcement in Oregon’s largest city.

US agents repeatedly fired what appeared to be tear gas, flash bangs and pepper balls early on Monday to clear a mass of protesters outside the Mark O. Hatfield courthouse in Portland. Some protesters had climbed over the fence surrounding the courthouse, while others shot fireworks, banged on the fence and projected lights on the building.

The federal courthouse has been a place of contention as the city has seen nightly protests for two months since the death of George Floyd in Minneapolis in May.

The protest late on Sunday started peacefully. But things intensified as the night wore on. US agents declared an “unlawful assembly”, and just after 1am, confronted protesters on the street and worked to clear the area. Several people were seen being detained, but it was not clear how many may have been arrested.