A woman and her three-month-old daughter have died under mysterious circumstances in Manoharganj upazila of Comilla.
The deceased were identified as Khaleda Akhter Khuki, 20, and her daughter Farzana Akter Faria.
Five other members of their family have also fallen ill at Binoyghar Beparibaari area of the upazila.
Locals claimed that seven members of the family fell ill after taking water from a tube-well set up at their house on March 3.
Faria died on the way to Comilla Medical College Hospital while Khuki died at the hospital on Monday.
Upazila Health and Family Planning Officer Dr Mohammad Shahajahan Sarkar said they were looking into whether the mother and children died taking water of the tube-well or for any other reason.