One person shot in 2nd night of unrest in Milwaukee

At least one person was shot and an officer was injured in Milwaukee late Sunday during a second night of violent protests over a fatal police shooting.

More than 100 people holding candles and paper signs reading "BlackLivesMatter" had gathered early Sunday night at a local park, then marched to the site of the shooting. The peaceful protest was later disrupted by skirmishes.

Police said angry crowds pelted officers with rocks, concrete and debris after authorities declared the gathering in the Sherman Park neighborhood of Milwaukee an unlawful assembly and threatened arrests.

Photos from the scene:

One injured cop was taken to the hospital after a rock broke the windshield of his squad car, according to the force.

The violence escalated after 11 p.m. local time (12 a.m. ET) when gunfire was reported. Police said officers used an armored vehicle to rush one shooting victim to the hospital. The 18-year-old victim was being treated for serious injuries, according to NBC affiliate WTMJ.

WTMJ reported that while most of the protesters had dispersed by around 1 a.m. local time, isolated incidents continued. A car was set ablaze and more shots were reported, according to police.

The force said officers were making "multiple" arrests.

Officials have been appealing for calm since the violence erupted Saturday night in wake of the fatal police shooting of Sylville K. Smith, 23. Businesses were burned, a cop car was torched and property destroyed.

Police have said Smith — who was black — was armed with a handgun and fleeing a traffic stop on foot when he was killed by a 24-year-old African-American officer.

Body camera video that hasn't been released shows that there was a "credible threat" to the officer, according to Milwaukee Police Chief Edward A. Flynn.

At one point Smith — who authorities said had a "lengthy" arrest record — turned toward the officer with the gun in his hand, Flynn said. Authorities said Smith's gun held 23 rounds.

The state is investigating the shooting.

The officer has been placed on administrative duty pending an investigation. He has also left town in light of threats against him and other police officers, according to Flynn.

Smith's sister told The Associated Press that the family wants prosecutors to charge the officer who shot him.

Kimberly Neal, 24, spoke as supporters surrounded her at the vigil as she held a bouquet of blue balloons.

When asked about the violence, Neal said: "People stuck together and they are trying to stand up," for their rights.

The National Guard had been activated and put on standby Sunday.

Smith's death comes amid nationwide tensions over police use of force — which has spurred protests but also deadly violence against officers.

The Milwaukee Police Association hit back at the suggestion race may have played an issue in Smith's shooting and condemned the riots.

"Leadership must denounce violent riotous behavior! There can be no appropriateness in rationalizing terrorist-like actions," it said in a statement. "The thugs that caused this are certainly terrorists and must be held accountable."