The Mongla port municipal election is to be held on 16 January.
Mayoral candidate Sheikh Abdur Rahman has demanded exemplary punishment of those responsible for this incident.
Officer-in-charge of Mongla police station Md Iqbal Bahar Chowdhury told Prothom Alo, "We are yet to bring those culprits into book. We are trying to catch those criminals after scrutinising CCTV footage."
He said local Awami League has complaint verbally but is yet to file any formal case in this regard.