Eighteen cases have been filed so far and 21 arrested over clashes and vandalism in Brahmanbaria for three days until Sunday.
Fifteen cases were filed with Brahmanbaria Sadar Model Police Station, two with Ashuganj Police Station, and one with Sarail Police Station on charges of vandalism and arson attack, police sources said.
Over 10,000 were made accused in the cases, mostly unnamed.
Of the accused, Sadar police arrested 18 and Ashuganj police three, they said.
Clashes involving Hefazat left nine people dead in police firing in Brahmanbaria during anti protests against Indian Prime Minister Narendra Modi.
On March 28, Hefazat called a countrywide dawn-to-dusk hartal protesting police action on their anti-Modi processions in Dhaka, Chattogram and other districts.
Hefazat-e-Islam activists attacked a Chattogram-bound train at Talshohor Rail Station in Brahmanbaria town during the general strike.
Also, the hartal supporters carried out vandalism and arson attacks on government and private establishments.