Where those who are harmless are said to have no weapons? (4,6)
I believe the answer is:
east london
'where those who are harmless are said to have no weapons?' is the definition.
(cockney harmless is 'armless)
This is all the clue.
(Other definitions for east london that I've seen before include "South African port?" , "Poplar found in this" , "Cockney part of the capital" .)