Demonstrations in Portland by right-wing and left-wing protesters turned violent — yet again, with protesters hurling rocks at each other and getting into fights.

On Saturday afternoon, images showed hundreds of people gathered near the Multnomah County Justice Center in Oregon’s biggest city. Many of them wore helmets and carried makeshift shields.

Right-wing groups had announced a rally near the building Saturday afternoon that quickly drew counter demonstrators.

Portland police issued a warning about two hours after the demonstrations began, warning that officers were prepared to start using crowd control weapons if the violence did not end.

The Saturday afternoon clashes followed predawn clashes between police and about 200 left-wing protesters outside a different police precinct.

Demonstrators hurled bottles and rocks at officers and pointed lasers at them, damaging police cars and causing minor injuries for several officers, Portland police said in a statement.

Violent demonstrations have gripped in Portland for months, following the police killing of George Floyd in May in Minneapolis police custody.

On Friday, people in a group of about 100 sprayed the building with graffiti, hurled rocks and bottles at agents and shined laser lights at them, Portland police said.

Also Friday, a number of federal buildings across the city were closed as the FBI investigated a car bomb threat.