They had fled across the border to Bangladesh amid heavy fighting between the Myanmar military and rebel insurgents in Rakhine
Twenty others were injured in the accident that took place in the Upazila's Talukdar Bazar area near the Bangabandhu Bridge around 12:30pm on Sunday.
The authorities identified one of the fatalities as Shapla Khatun, 27, wife of Rashed Mia of Gaibandha's Saghata Upazila. The two other victims could not be identified immediately.
The injured were taken to Bangamata Sheikh Fazilatunnesa Mujib General Hospital.
“The motorcycle also fell into the ditch. Two passengers of the bus and a motorcycle rider died on the spot.”
Shapla was riding pillion on the two-wheeler with her brother, who was also injured in the crash, according to Manjil.