A burst of shootings over the weekend left 12 people dead and dozens more wounded in Chicago, the latest evidence of runaway gun violence in the third largest US city. Police blamed much of the carnage on gangs, which run rampant in some of the city's poorest and predominantly minority neighborhoods on the west and south sides.

At one point, 40 people were shot in the span of seven hours, according to a tally compiled by the Chicago Tribune, with bystanders as well as alleged gang members among the casualties. Police said in some of the incidents shooters sprayed bullets indiscriminately into large groups in rival territories, where people had gathered for outdoor events. In all, 66 people were shot between Friday evening and Sunday night, according to the official police tally. "What we saw this weekend, it just rips at everything that I believe in," said Chicago Police Chief Eddie Johnson, "because I know, as a city and as a neighborhood, we can do better."