CHICAGO (AP) — As many as two gunmen opened fire on a group of people standing on a Chicago sidewalk at a barbecue Tuesday night, killing one man and wounding six other people, Chicago police said Wednesday.

The shooting happened in the city's Bronzeville neighborhood, about two blocks from police headquarters. The attackers approached the group on foot before firing. An earlier dispute in a nearby park may have contributed to the violence, Chicago police spokesman Anthony Guglielmi said. One of the shooting victims has a history with police and was shot in 2011, Guglielmi said.

"Detectives are exploring whether that man was the intended target or whether this was a verbal dispute that escalated into senseless violence," Guglielmi said.

The man who was killed was Alfred Mitchell Jr., 28, of Chicago, who was pronounced dead at Northwestern Memorial Hospital, authorities said.

The six survivors, including five women, were treated for gunshot wounds to the knees, legs or buttocks. They range in age from 21 to 46 years old.

No one has been arrested in the attack. Police have increased patrols and detectives are continuing to investigate, including looking for video of the incident. Anti-violence activist Andrew Holmes said he's hopeful nearby surveillance cameras captured images of the suspects or other clues.

"If you know who committed this crime, took off in that car, turn those individuals in; and, most important, we need that weapon that was discharged, too," Holmes said.

The shooting incident comes after Chicago police reported 74 homicides in the city during the month of July.