Warning of imminent danger (3,5)
I believe the answer is:
red alert
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">warning of imminent danger</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for red alert that I've seen before include "Urgent warning" , "Scarlet warning of imminent danger?" , "State of readiness for imminent crisis" , "Severe 1 dn" , "State of readiness for imminent threat" .)