Forty people were injured when a picnic bus carrying them turned turtle at Naoda in Panchbibi upazila of Joypurhat district.
The accident occurred early on Friday.
The injured Golam Mostafa said the Dinajpur-bound bus carrying 50-60 people turned turtle around 4:30am, leaving 40 passengers injured.
Later, the injured were taken to Joypurhat District Modern Hospital.
The hospital's emergency unit doctor Nurunnabi said: “Of the injured, 21 have been admitted here while the rest were released after primary treatment.”
Assistant Police Super Ruhul Amin said: “The accident took place as a driver fell a sleep while driving.”
He said the driver fled the scene soon after the accident.