Three cousins drowned at Pashchim Kanaimajhari village in Chattogram's Chandanaish upazila on Sunday.
The victims were Sifatul Islam Abir, 6, son of Md Helal Uddin, Md Ifti, 4, son of Oman expatriate Md Kawsar Alam, and Moinul Islam, 4, son of late Joynal Abedin of the village.
Police and family sources said the trio accidentally fell into a ditch near their house while playing on its bank. Family members later found them floating on the water.
They were rushed to Chattogram Medical College Hospital where on-duty doctor declared them dead.
A pall of gloom descended on the families after the incident, said Keshab Chakrabarty, officer in charge of Chandanaish Police Station.