Missiles were thrown as trouble flared again on the streets of the US city of Portland.
The arrest of a leading racial justice campaigner, during a protest in the city, has galvanised Black Lives Matter groups.
Demonstrators took to the streets again on Monday night and police broke up a protest outside a police substation after they said protesters shined strobe lights at officers and hurled eggs and water bottles at them.
Nine people were arrested when clashes broke out at the protest that lasted into the early hours of yesterday morning, with some protesters throwing rocks and golf balls in the mayhem. Portland has endured more than two months of often violent, nightly protests since George Floyd was killed in Minneapolis.
Authorities said the prominent activist, Demetria Hester, will not be charged following her arrest after a protest that started on Sunday night and turned violent outside the union headquarters for Portland's police. Her arrest drew a sharp rebuke from national Black Lives Matter activists.