A case was filed against 50 BNP leaders and activists on Saturday following assault on a police officer by some BNP activists at Alaipur in the district town.
Natore thana SI Abdul Majid filed the case.
Sources said as part of the central programme district BNP activists arranged a meeting and staged demonstration in the town. At one stage, some BNP activists were locked into altercation with SI Abdul Latif during their meeting.
Later, the BNP activists assaulted him at the meeting venue, the police said.
The police arrested BNP activist Ali Hossain from Hazratpur in Sadar upazila early Sunday in connection the case.
Source : New Age