Police in the US have clashed with protesters in St Louis for a second consecutive night, a day after a policeman killed a black teenager.
Around 400 demonstrators clashed with police in riot hear in the south of the city.
Vonderrit Myers Jr, 18, was shot dead by a police officer on Wednesday after police said he fired several shots at them in the St Louis neighbourhood of Shaw.
In footage seen on social media, demonstrators said police at one point rushed toward them and pepper-sprayed them.
One man could be seen later having milk and water poured over his eyes.
Police did not immediately respond to requests for information about the pepper spray reports, or whether there had been any injuries or arrests.
The St Louis area is bracing for further unrest over the August killing of unarmed black teenager Michael Brown by a white police officer, with Mr Myers' killing expected to add fuel to the fire.
Several civil rights organisations and protest groups, including Hands Up United, planned to mark the weekend with marches and rallies in St Louis and the suburb of Ferguson, Missouri, where Mr Brown was killed.
"We never advocate violence ... But I do know that people were angry last night and they will be out this weekend," said Tory Russell, a leader of Hands Up United. "I don't know what they are going to do."
At least 6,000 people have registered on an organising website for the "weekend of resistance" events in and around Ferguson, which start today with a "justice now" march to the office of St Louis County Prosecutor Bob McCulloch.
The weekend is to be capped with actions of "civil disobedience" on Monday.
Organisers said they are also planning to create a "memory altar" to victims of police violence and to hold a candlelight march carrying a coffin to the Ferguson Police Department.
Ferguson Mayor James Knowles said law enforcement officers throughout the area are planning for large crowds and possible violence.
"There are a lot of people coming into town," said Mr Knowles.
"We are going to be prepared. There is intel out there that there are people wanting to do bad things. And people who want to cause a problem are going to use that (the shooting on Wednesday) as a rallying cry," he said.
The police department would not identify the 32-year-old officer who shot Mr Myers while he was off duty working for a private security company, but said he was not hurt and has been placed on administrative leave as the shooting is investigated.
Relatives of Mr Myers said he did not have a gun, the St Louis Post-Dispatch reported.
