US President Donald Trump and his Democratic rival Joe Biden have clashed over the violence that has erupted at protests in Portland, Oregon.
Mr Trump blamed the Democrat mayor of Portland, Ted Wheeler, for allowing the “death and destruction of his city”.
But Mr Biden said the president was “recklessly encouraging violence”.
A man was shot dead in Portland on Saturday as elsewhere in the city a pro-Trump rally clashed with Black Lives Matter protesters.
Portland has become a flashpoint for demonstrations against police brutality and racism since the police killing of African-American George Floyd in Minneapolis on 25 May triggered a wave of national and international outrage.
Mayor Wheeler warned against people coming to the city to seek revenge amid a flurry of social media posts.
“For those of you saying on Twitter this morning that you plan to come to Portland to seek retribution, I’m calling on you to stay away,” he said.
He also hit back at Mr Trump’s criticism, saying it was the US president who had “created the hate and the division”.
“I’d appreciate it if the president would support us or stay the hell out of the way,” he said. Some activists have called for the mayor’s resignation, saying he was not capable of resolving the protests.