Attacks one in the streets (6)
I believe the answer is:
stones
'attacks' is the definition.
(I've seen this before)
'one in the streets' is the wordplay.
'in the' indicates putting letters inside.
'streets' becomes 'sts' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'one' inserted into 'sts' is 'STONES'.
Can you help me to learn more?
(Other definitions for stones that I've seen before include "Attacks" , "Small pieces of rock" , "They've been rocking and rolling since the 1960s" , "Rolling rock group" , "Cherry pips" .)