Three doctors of the Sheikh Fazilatunnessa Mujib Memorial KPJ Specialized Hospital & Nursing College in Gazipur have tested positive for the novel coronavirus.
The authorities have collected samples of 21 other hospital employees for coronavirus testing.
Gazipur Civil Surgeon Md Khayruzzaman said, "Samples of the three doctors were sent to the Institute of Epidemiology, Disease Control and Research (IEDCR) on Sunday as they were showing symptoms of Covid-19.
"On Monday, the test results came and all of them were positive."
The three doctors are currently in isolation, he said.
Samples of another 21 employees of the hospital have been collected and sent to the IEDCR on Monday, he added.
The three infected doctors are from the hospital's radiology, plastic surgery and nephrology departments, hospital official Abul Hasan said.
Meanwhile, an employee of the district's civil surgeon's office has also tested positive for the virus. His sample was collected and sent to the IEDCR on Sunday.
The patient does not have many symptoms and is currently in isolation at his residence.
So far, two employees of the civil surgeon's office have been diagnosed with Covid-19.
The previous employee, a nightguard, came in contact with the civil surgeon and 12 other employees of the hospital.
All of them are currently staying in home quarantine, Gazipur Sadar upazila health and family welfare officer Dr Shahin said.