The cold spell in the north and north-western regions of the country is likely to continue for the next couple of days and the temperature might dip further in some parts, said Dhaka Met office.
Thick fog will shroud the river basins and disrupt the operations of river ports till midday today.
The cold wave is sweeping through Khulna, Barisal, Rajshahi, Rangpur and Sylhet divisions and Madaripur district.
The overall temperature is likely to increase by the day after tomorrow.
The lowest temperature yesterday was recorded at 6.8 degrees Celsius in Chuadanga, while it was nearly 12 degrees Celsius in Dhaka.
Our Benapole correspondent reports: Four elderly women died from cold-related diseases in different areas of the port thana over the last three days until yesterday.
The deceased are Rahila Begum, 81, Horidasi, 85, Ayenamoti Turi,75, and Asia Khatun, 78.
Atal Das of Star Medical Diagnostic Centre said cold-related diseases have spread alarmingly in recent days, with the mercury dipping to nine degrees Celsius in Benapole.
The number of patients in hospitals has increased every day over the last week, he added.
Our Munshiganj correspondent adds: Ferry services on Mawa-Kawrakandi route were halted between 5:00 am and 7:30am yesterday due to thick fog.
Four ferries got stranded in the middle of the Padma, causing immense sufferings to thousands of passengers.
Nearly 200 vehicles including cargo trucks had to wait for hours on both sides of the river to cross it.
The ferry services on this route have so far suffered a total of 117 hours of halt since December 9 due to poor visibility.
Sekhor Chandra Roy, assistant manager of Bangladesh Inland Water Transport Corporation (BIWTC), said ferry services on the Mawa-Sharishabari route were also stalled due poor navigability.
Though the dredging of the river started on December 23 to keep the ferry services in operation, it was later postponed in the face of protests by local people against dumping of excavated sand in a nearby parking yard.