This assault involved elite soldiers (3)

I believe the answer is:

sas

I'm a little stuck... Click here to teach me more about this clue!

'elite soldiers' is the definition.
(Special Air Service)

'this assault involved' is the wordplay.
'SAS' is hidden in amongst the letters.
However, I'm uncertain how the hidden word is indicated.

Can you help me to learn more?

(Other definitions for sas that I've seen before include "Specialist regiment of the British army, in short" , "Commando-type unit of the British army" , "Elite fighting force" .)

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.