Authorities on Thursday locked down the Anderkilla branch of Bank Asia in Chattogram and instructed 15 employees to stay in quarantine.
"A patient from Chattogram's Sagorika area, who came positive in coronavirus test yesterday, had visited the branch on April 1," Kotwali Police Station's Officer-in-charge Mohammad Mohsin told The Business Standard.
Branch officer Ali Tarek Pervej said, "We all are currently staying in our homes. The office has been shut down."
Earlier on Wednesday, three patients were diagnosed with the coronavirus in Chattogram.
The infected patients are residents of Halisahar, Sitakunda and Sagorika areas.
The port city reported its first coronavirus patient aged 67 on April 3 amid a countrywide shutdown to curb the spread of the virus. Two days later, the patient's 25-year-old son also tested positive for the virus.
The city currently has five active cases of Covid-19. All the patients are currently in isolation and undergoing treatment.
So far 21 people have died from the virus in Bangladesh and 330 are infected with it.