Officials in the US city of Philadelphia announced a curfew on Wednesday following two nights of unrest over the latest police killing of a black man.
The citywide order will last from 9pm until 6am on Thursday, according to a statement on the city government's website.
Thousands of people have taken to Philadelphia's streets, with looting and violence breaking out, after police on Monday shot dead 27-year-old Walter Wallace Jr, who authorities say was carrying a knife.
His family said he suffered from mental health issues and asked why officers did not taser him instead.
Mr Wallace's death and the subsequent demonstrations have also revived a political clash between Republicans and Democrats less than a week before the election.
"It's a terrible thing, what I am witnessing is terrible and frankly that the mayor or whoever it is that's allowing people to riot and loot and not stop them is also just a horrible thing," President Donald Trump told reporters.
The US has seen a wave of protests and rioting since the police killing of George Floyd in May in Minnesota, when an officer was filmed pressing his knee to handcuffed Mr Floyd's neck until he went limp.
Many of the protests have accused the police of racism and brutality, but Mr Trump has focused on the unrest to bolster his claims to be the "law-and-order" candidate in his election battle against Joe Biden.
On Tuesday, the Democratic challenger and his running mate Kamala Harris said in a statement that their "hearts are broken" for Mr Wallace's family.
But they also called on demonstrators to protest peacefully.
"No amount of anger at the very real injustices in our society excuses violence," Ms Harris and Mr Biden said.
"Looting is not a protest, it is a crime. It draws attention away from the real tragedy of a life cut short."
Two officers shot Mr Wallace on Monday afternoon after he refused to drop the knife as his mother tried to restrain him.
A bystander’s video of the shooting of Mr Wallace was posted on social media on Monday and showed him approaching two police officers who had drawn their guns and warned him to put down his knife. The officers were backing up before the camera cut briefly away as gunfire erupted and Mr Wallace collapsed.
On Tuesday, Pennsylvania Governor Tom Wolf's office announced the deployment of several hundred National Guard troops to the city "to protect the right to peacefully assemble and protest while keeping people safe".
Philadelphia's police commissioner has launched an investigation into the shooting.
