They are undergoing treatment at the Isolation Unit of Mohammad Ali Hospital, according to hospital sources.
Though doctors of the hospital said they are not coronavirus patients, the samples have been sent for proper diagnosis.
Dr Shafik Amin Kajol, resident medical officer of the hospital, said at present there are five patients -- a woman, a minor and three men -- with coronavirus symptoms. The minor has been suffering from pneumonia. Though the physical condition of four people has improved, samples have been sent for better treatment.
The Rajshahi Medical College Hospital (RMCH) started conducting coronavirus tests at its laboratory on Wednesday.
Meanwhile, the government has announced the death of another coronavirus patient in the country. So far, Bangladesh has confirmed 54 cases and six deaths.
COVID-19, first reported in China, has so far infected 872,972 people globally and killed 43,275 of them, according to Worldometer.