Encountered force in London (3)
I believe the answer is:
met
I believe this is a double definition.
'encountered' is the first definition.
('meet' can be a synonym of 'encounter')
'force in london' is the second definition.
(Metropolitan Police Service of London)
(Other definitions for met that I've seen before include "Came across - police in London" , "Encountered pro tem" , "Encountered, came into contact" , "satisfied" , "Came together, encountered" .)