Seven suspects were arrested in connection with the attack on an additional police superintendent when a team attempted to resist extortion from vehicles in Narsingdi Sadar upazila.
Earlier, in-charge of town police outpost Sohel Ahmed filed a case naming five people and 25 to 30 unidentified ones with Sadar Police Station on Saturday night.
Extortionists attacked a police team in Arshinagar area of the town when they attempted to stop extortion from vehicles and detained two extortionists on Saturday.
The miscreants attacked Additional Superintendent of Police (Sadar Circle) Anwar Hossain, leaving him injured.
Other police personnel and locals rescued the injured officer and took him to Narsingdi Sadar Hospital and later he was transferred to Central Police Hospital in Dhaka.
A video showing a man carrying a stick hitting the police official went viral on social media.
Superintendent of district police Menhajul Alam said they were verifying the involvement of the arrestees in this incident.
He also said that details of the investigation will be shared later as efforts are on to arrest the remaining suspects.