The place is a cesspool of neglect, poverty, criminality and desperation. Its population is a volatile mix of locals, immigrants (many of whom are illegal), workers, unemployed and criminals. To top it all, it resides on a steep slope. 

I have no idea how the authorities think they can make this place liveable, without spending hundreds of millions on terracing and installing sewerage, water and power. It is also probably one of the most dangerous spots in the city. 
Blocking will require some form of census, and many if it's residents don't want that, for obvious reasons.

The only way to get it right is for the community itself to identify the criminal elements that live among them, isolate them, and then participate in the "blocking" as temporary city employees.  The city will have to break its own laws to expedite this process.