Sherpur was put on lockdown on Wednesday night after detection of four novel coronavirus patients in the district.
The restrictions will remain effective until further order, said a press release signed by Anar Kali Mahbub, a magitrate at the district administration.
The lockdown means a ban on the flow of people in and out of the district during the period of lockdown.
Meanwhile, law enforcers have been instructed to stay alert so that none can defy the lockdown.
Some 1,231 people caught the novel coronavirus and 50 died from the virus in Bangladesh as of Wednesday since the country detected its first cases on March 8.