A pregnant woman diagnosed with coronavirus on Saturday fled from the Chougachha Health Complex.
The 28-year-old is a resident of Banurhuda village in the upazila.
Upazila Health and Family Planning Officer Dr Lutfurnnahar said the woman got admitted to the health complex with cough, fever, and sore throat on Thursday.
They took the samples of three people, including the woman, and sent to Genome Centre of Jashore University of Science and Technology for coronavirus test. Of them, the woman was found infected.
Following the test result, the local administration put the entire upazila under lockdown, the official added.
On Wednesday, two people tested positive for coronavirus in the upazila.