CHICAGO — A Chicago police officer fatally shot a man Saturday evening on the city’s South Side, angering nearby residents who gathered at the scene in large numbers and confronted officers for several hours.

The shooting was the latest in recent years to expose deep-seated mistrust between the Chicago police and residents of predominantly black neighborhoods on the South and West Sides.

Fred Waller, the chief of patrol for the Chicago police, said Saturday’s encounter started when officers noticed a man with a bulge on his waistline that they believed could be a gun. He said a confrontation broke out after officers approached the man, who was identified on Sunday as Harith Augustus, 37, and that an officer fired fatal shots.

“When they approached him, he tried to push their hands away,” Chief Waller said. “He started flailing and swinging away, trying to make an escape. And as he made an escape, he reached for the gun.”