Explosive laid by soldiers in this location (4)
I believe the answer is:
here
'in this location' is the definition.
(I've seen this in another clue)
'explosive laid by soldiers' is the wordplay.
'explosive' becomes 'he' (abbreviation for high explosive).
'laid by' is a charade indicator (letters next to each other).
'soldiers' becomes 're' (Royal Engineers).
'he'+'re'='HERE'
(Other definitions for here that I've seen before include "In this place - present" , "Hither" , "In attendance" , "At this stage" , "final clue?" .)