Over 400 people were sued in connection with two cases over the violence in Kutubdia that left at least three people dead during the recent 60-hour shutdown called in by the BNP.
Police filed the two cases on Wednesday 8:30pm.
Cox's Bazar police Additional Superintendent Tofayel Ahmad said the two cases were filed over attack on police, murder and anti-terrorism acts.
Violent clashes occurred between law enforcers and supporters of the shutdown, led by opposition BNP and Jamaat-e-Islami, in Dhurung Bazar area on Tuesday, the last day of the 60-hour hartal.
The ASP said three bodies were recovered from the site after the situation had calmed down.
Opposition activists claimed the casualties were caused from bullets fired by police.