Gunfire at Ferguson protest marking Michael Brown killing
Gunfire broke out in Ferguson, Missouri, after a car hit a protester marking the second anniversary of the death of Michael Brown.
No one appeared to have been wounded by the gunfire. The extent of the hit protester's injuries are unknown.
It followed a day of peaceful commemorations to remember 18-year-old Michael Brown, who was killed by a white police officer in 2014.
Ferguson has been a flashpoint for protests since the fatal shooting.
The demonstrations spread to other US cities after a jury decided not to charge police officer Darren Wilson over the killing.
The death of Michael Brown sparked protests nationwide over the fatal shootings of other black men and boys by police officers.
The car hit the protester during an evening march along a major street in Ferguson.
Witness Sharon Cowan told AP news agency that the driver, a woman, "knocked the shoes off his feet... Hit him, and he rolled and he bounced."
Photos showed the protester appearing to be conscious and being carried away. He is thought to have been taken to hospital.
Shortly after he was hit, a number of protesters began chasing the car, pulling out guns and firing them as they did so, witnesses said.
"The bullets started flying, and I started screaming," said Heather DeMian.
Ferguson Police spokesman Jeff Small said it appeared that the car driver had not intended to knock over a protester, and she was being "very co-operative", the St Louis Post-Dispatch newspaper reported.
He said there were bullet holes in the car, but no-one was injured.
Earlier in the day, Michael Brown's father remembered his son as someone who "built families up, opened the eyes of the world and let them know this ain't right.
"This colour is beautiful. Black is beautiful," he said.
What happened in Ferguson on 9 August 2014?
The exact details of what happened that day remain disputed by police, eyewitnesses and family members.
What is known for certain is that around midday on 9 August 2014, police officer Darren Wilson was driving a police car and encountered Mr Brown and a friend walking down a street.
Minutes later 18-year-old Mr Brown was dead, suffering at least seven gunshot wounds, according to county prosecutor Bob McCulloch. His body lay in the street for four hours before it was removed.
Mr Wilson fired a total of 12 bullets, though investigators were unclear exactly how many of the 12 struck Mr Brown. One injury may have been a re-entry wound.