Stabbings in Sheffield and Postcode Gangs

In which areas are these crimes occuring, has it for instance spread to the Broomhill/ Hunters Bar area?

I don't even know what a postcode gang is O.o

Chaiboub, known as GT for Global Threat, was a gifted, popular and generous teenager with an easy way of making friends among a group whose style of rap music translated their common experience into a poetic but incessant street patois. He was shot on the street pitch where he is also said to have dealt crack cocaine...Chaiboub always knew the risks of setting himself up as a “true Sheff soljah”. He went as far as predicting his own death in one of his raps, singing: “If you don't watch out the last thing you'll hear is click, click, pow.”

It's a group of people from a specific postcode who tend to show animosity to gangs from other postcodes.

In which areas are these crimes occuring, has it for instance spread to the Broomhill/ Hunters Bar area?

It is a traditionally Northern, predominantly working-class industrial city just like Manchester or Leeds so there's going to be a high proportion of immigration which in turn breeds a high proportion of drugs and gun-crime therefore equalling the deaths of people caught up in gang violence. Tell me if my logic is flawed?