CHICAGO (AP) — Maybe it is the splintering of established drug gangs that has young men grabbing the tools of their trade — handguns — to jockey for position? Or it is that rival gangs, once miles apart in different public housing complexes, suddenly finding themselves sharing the same street corner?

Whatever the reasons, Chicago has seen a spike in its homicide rate — with eight killed and at least 35 wounded in a spasm of gunfire last weekend alone — that has authorities scrambling to put more police on the street and some frightened residents retreating deep into their homes.