The deceased were identified as Mahmuda, 25, wife of Rubel Hossain and their son Momin, 6, hailing from Mehendiganj of Barishal.
Abu Taher, officer-in-charge of Chandpur River Police Station, and Nurul Islam, master of Kirtankhola-10 launch, confirmed the casualties.
Jhantu, manager of Kirtankhola-10, said Dhaka-bound Farhan-9 launch from Hularhat in Bhandaria hit their vessel around 1:30am.
“Two people were killed on the spot and a large part of the launch was damaged,” he added.
Kirtankhola-10 left Barishal river port around 9pm for Dhaka with 700 passengers.
Mahmuda’s husband Rubel said they were returning to Dhaka from their village home. “My wife and son were asleep when the accident took place,” he said adding that he was not sleeping.
Police recovered the bodies after Kirtankhola-10 reached Sadarghat Launch Terminal, said Rezaul Karim Bhuiyan, officer-in-charge of Sadarghat River Police Thana.