One of the two patients fled from the coronavirus isolation unit of Bhola General Hospital on Wednesday.
The patient got admitted with fever and cough on Tuesday night, but has not been seen at the hospital after 1pm, Bhola Civil Surgeon Dr Ratan Kumar Dhali said.
The escapee, a staff of Sheltech Tiles Industries in Bhola hailing from Joypurhat, was kept in the isolation unit as a suspected COVID-19 patient.
Dr Dhali said they informed police about the matter.
The patient's samples were supposed to be sent to Dhaka on Wednesday, said the health official.
Hospital sources said two young men with fever, cough and influenza came to the hospital on Tuesday night. They were kept at the isolation unit as they showed coronavirus symptoms.
Another patient hailed from Razapur Union of Bhola Sadar upazila.
Meanwhile, the local administration has asked two more overseas returnees to stay in home quarantine, raising the number of people in home quarantine to 427 in the district.
So far, 258 people completed their 14-day home quarantine in Bhola.