He was contesting as an independent candidate in the Dhaka-17 parliamentary by-election.
He was reportedly attacked while he was leaving the polling centre in Banani.
Police are reviewing video footage of the incident to identify the other assailants, Additional Commissioner Harunor Rashid told bdnews24 at a media briefing on Tuesday.
Legal action will also be taken to address any neglect of duty on the police's part, according to him.
The actor has not lodged a complaint over the matter so far.