The ferry MV Miraj-4 sank around 3:30 pm (local time) at Daulatpur while on its way to Sureshwar from Sadarghat in Munshiganj district, Deputy Commissioner Saiful Hasan said.
Two ships left Narayanganj for Munshiganj to join the rescue operation, the Daily Star reported.
The ferry was caught in a storm this afternoon and sank near Daulatdia in Munshiganj, about 50 kilometres from here.
Hasan said six bodies, including that of a child, have been recovered from the river so far.
The coast guard, district administration and local people are engaged in the rescue operation.
Mahmud Hossain, a transport inspector for Bangladesh Inland Water Transport Authority (BIWTA) in Dhaka said MV Miraj-4 left Dhaka at 1 pm.