Around 250-300 unnamed people were made accused in a murder case while 75 named and 300 unnamed people were sued in the other case filed on charge of assaulting police, the OC said.
Police have so far arrested ten people in this connection, the OC added.
On Monday, BNP leaders and activists gathered in front of their district party office at Kalinath Roy Bazar in Sadar upazila on Monday morning to hold a rally as part of BNP's demonstration programme.
At one stage, police obstructed them when they tried to stage demonstrations at Kalinath Roy Bazar around 11:30 am.
The leaders and activists pelted brickbats targeting police, prompting them to fire bullets and tear gas shells, triggering a clash that left one person dead and at least 30 people injured, said police.