Tension flared again yesterday night, with one person shot and a police officer injured, in the Milwaukee area where the fatal shooting of a suspect by an officer had sparked rioting, prompting Wisconsin's governor to activate the National Guard.
Police violence against African-Americans has set off intermittent, sometimes violent protests in the past two years, igniting a national debate over race and policing and giving rise to the Black Lives Matter movement.
After peaceful vigils by small groups of demonstrators earlier, Milwaukee police said late on Sunday night they had rescued one shooting victim, who was taken to hospital. It was not known whether the injured person was a protester. One police officer was hospitalised after a rock smashed a patrol car windshield, the MPD said.
Police said they began attempting to disperse crowds after shots were fired and objects, including rocks and bottles, were thrown by some protesters. Several arrests were reported.
About 20 police in riot gear faced a group of more than 100 protesters in a tense standoff that continued into the early morning hours, punctuated by sporadic reports of gunfire.
Despite the violence, police said the National Guard had not been called in, as authorities worked to restore order. Wisconsin governor Scott Walker took the precaution of activating the National Guard in case more violence broke out over the death of Sylville K Smith, 23, who was shot while trying to flee from an officer who had stopped his car.
Aiming to reassure the community that the police acted properly, chief Edward Flynn said yesterday he had viewed video from the officer's body camera and it showed Smith had turned toward him with a gun in his hand after a traffic stop.
The Sherman Park neighborhood, where a heated confrontation between residents and officers clad in riot gear turned violent overnight, had been peaceful at dusk.
About 200 people lit candles and gathered near the spot where Smith was shot. A few officers looked on as faith and community leaders implored protesters to restrain their anger.
The previous night, shots were fired, six businesses were burned and police cars damaged before calm was restored in the area, which has a reputation for poverty and crime. Seventeen people were arrested, and four officers were injured.
At a news conference with Mayor Tom Barrett, Flynn said the officer who fired the fatal shot was black and media reports also identified Smith as black.
He said a silent video of the incident appeared to show the officer acting within lawful bounds. He said the officer stopped Smith's vehicle because he was behaving suspiciously and then had to chase him several dozen feet on foot into an enclosed space between two houses.
He said the moment when the officer fired his weapon could not be determined because the audio was delayed.
The mayor said Smith did not drop the gun as ordered before he was shot. Smith had a lengthy arrest record, Barrett said, and officials said earlier he was carrying a stolen handgun loaded with 23 rounds of ammunition when stopped.