Protesters in Chicago are demanding answers after the fatal shooting of a black man by police prompted violent confrontations in the Illinoiscity.

"The whole damn system is guilty as hell," dozens chanted on Saturday just hours after police shot and killed 37-year-old Harith Augustus in the South Shore neighbourhood of Chicago.

Augustus is known in the community as Snoop the barber, local media reported.

The city's police patrol chief Fred Waller told reporters late on Saturday that Augustus was shot after police officers on foot tried to question him because "the bulge around his waistband" suggested he was armed. Augustus became combative and eventually broke free from the officers, Waller said.

"They thought he appeared to be reaching for a weapon, which he did have a weapon on him, and the officers tragically shot him," Waller told reporters, adding that police recovered a semi-automatic weapon.

Augustus waspronounced dead at the hospital.

Almost immediately after the shooting, a crowd of onlookers and activists descended on the scene. Video circulating on social media shows tense confrontations between police and protesters.

Local journalist Nader Issa, who reports for the Chicago Sun-Times, wrote on Twitter that at one point the situation "severelyescalated when Chicago Police officers moved their line forward".

He added: "Officers hit multiple protesters with batons, and protesters punched officers back."

Speaking to Al Jazeera, Issa said the tension was so high immediately after the shooting that "it was clear there was going to be a confrontation between Chicago Police and protesters at some point". (Aljazeera)