The drive was conducted from Jamrildanga to Baroipara in Kalia upazila overnight.
The arrestees were identified as Tutul Sheikh, 38, Morshekh, 32, Jony Sheikh, 25 and Irfan Sheikh, 22 of Bishnupur village in the upazila.
Anisuzzman, assistant sub-inspector of DB, said the drive would continue for protecting mother hilsa and jatka.
The government has imposed a 22-day ban on catching, selling, hoarding and transporting of hilsa from Oct 14 to protect hilsa with eggs.
The ban will be effective until Nov 4.
Fisheries and Livestock Minister SM Rezaul Karim on October 12 said no one will be allowed to catch mother hilsa during this period.
“No boat will be allowed to ply spots in the river where mother hilsas roam. Members of Navy and the coast guard’s special monitoring team will work to prevent catching of hilsa,” he said at a press briefing on the implementation of ‘mother hilsa conservation drive-2020’.
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