This book constitutes selected and revised papers from the First International Workshop on Combating On​line Ho​st​ile Posts in ​Regional Languages dur​ing Emerge​ncy Si​tuation, CONSTRAINT 2021, Collocated with AAAI 2021, held as virtual event, in February 2021. 
The 14 full papers and 9 short papers presented were thoroughly reviewed and selected from 62 qualified submissions. The papers present  interdisciplinary approaches on multilingual social media analytics and non-conventional ways of combating online hostile posts.