US President, Donald Trump and his Democratic rival, Joe Biden have clashed over the violence that has erupted at protests in Portland, Oregon resulting in the death of an unnamed victim.
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 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 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.
In a series of tweets on Sunday, Mr Trump said that “Portland will never recover with a fool for a mayor”, and suggested sending federal forces to the city.
“The people of Portland, like all other cities & parts of our great Country, want Law & Order. The Radical Left Democrat Mayors, like the dummy running Portland, or the guy right now in his basement unwilling to lead or even speak out against crime, will never be able to do it!” he tweeted.
In a statement, Mr Biden said: “[Trump] may believe tweeting about law and order makes him strong – but his failure to call on his supporters to stop seeking conflict shows just how weak he is.”
Law and order is a major theme of President Trump’s bid for re-election, painting the Democrats and their candidate Joe Biden as soft on crime.
Earlier, acting US Homeland Security Secretary Chad Wolf said Democrats officials in Portland had allowed “lawlessness and chaos” to develop, saying “all options” were on the table to resolve the situation.
Democrats have responded by saying the violence is happening under Mr Trump’s presidency, and accuse the US leader of worsening the situation with his rhetoric.
The continuing violence on US streets brings into focus the evolving tone of Donald Trump’s election campaign – criticising cities run by Democrats, where much of the trouble has occurred, and framing himself as the law and order president.
This could however be a pivotal week as on Tuesday, the president will head to Kenosha, in the political swing state of Wisconsin, where violent protests followed the police shooting of Jacob Blake. The stated reason is for Mr Trump to meet local police and “survey damage from recent riots” and Americans will be watching to see if the president also reaches out to Mr Blake and his family and for any expressions of empathy for those who’re angry about police brutality.