The deceased are Nesar Ahmed, 65, Jamal Ali and Firoza Khatun, 78.
Hospital director Dr Rafikul Islam said their samples have been collected for coronavirus test.
So far 87 people died with coronavirus symptoms in the district, Dr Rafikul said.
Besides, a total of 29 died after being confirmed to have been infected by Covid-19 here, he added.
Civil Surgeon Dr Husain Shafayat also confirmed the matter.
Also read: Coronavirus: Bangladesh reports 42 deaths, 1,897 cases