Two police officers were shot and wounded late on Wednesday in Louisville, Kentucky, during protests against a US grand jury ruling decried by civil rights activists as a miscarriage of justice in the fatal police shooting of Ms Breonna Taylor in March.
The grand jury decided that none of the three white officers involved in the deadly police raid on Ms Taylor's apartment would be charged over causing her death, though one officer was indicted on charges of endangering her neighbours.
The indictment came more than six months after Ms Taylor, 26, a black emergency medical technician and aspiring nurse, was killed in front of her armed boyfriend after the three officers forced their way into her home with a search warrant in a drug trafficking investigation.
Her death became a symbol, and her image a familiar sight, during months of daily protests against racial injustice and police brutality in cities across the United States.
After the grand jury announcement, protesters took to the streets of Kentucky's largest city and marched for hours, chanting "No lives matter until black lives matter", amid sporadic clashes with police in riot gear.
The demonstrations remained mostly peaceful until several gunshots rang out as heavily armed police closed in on a throng of protesters at nightfall ahead of a 9pm curfew due to take effect. Gunfire erupted from the crowd moments after police fired chemical irritants and "flash-bang" rounds.
Two officers were shot and wounded, interim Louisville Metropolitan Police chief Robert Schroeder said. One suspect was arrested, and both wounded officers were in stable condition with non-life-threatening injuries.
The crowds largely dissipated after the shooting. Police said at least 46 arrests were made in all.
Sympathy protests of varying sizes also were held on Wednesday in several other cities, including New York, Washington, Atlanta and Chicago.
US Democratic presidential candidate Joe Biden said the grand jury failed to deliver justice for Ms Taylor but held out hope that the federal probe would do so. He also urged that protests be peaceful.
"Do not sully her (Ms Taylor's) memory or her mother's by engaging in any violence," he said.
Afterwards in the day, Mr Biden said black turnout was the linchpin to his hopes of winning the White House in November and reversing economic and social inequities that have held back African Americans.
"There's only one way to do it. We've gotta show up and vote."
Race relations have re-emerged as a flashpoint in US politics this year in the wake of killings of black Americans by police.
President Donald Trump said on Twitter that he was praying for both officers shot on Wednesday.
REUTERS