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 neighbourhoods on the west and south sides.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 neighbourhood, we can do better.”Authorities emphasized that the weekend shootings stood in contrast to a general decline in gun violence, where city figures show shootings down 30 per cent and murders down 25 per cent, compared to the same time last year.