Some 30 female students of a high school have fallen sick with symptoms of mass hysteria in Sadar upazila.
The incident took place at Syedpur High School by the Dhaka-Chattogram highway on Monday afternoon.
The sick students were taken to hospital.
Witnesses said 2-3 students of Class-VIII started laughing after the tiffin period.
Soon other students joined them.
Following the laughing epidemic, the students started to fall sick one after another.
Doctors at Sadar Hospital said the girls were attacked by mass psychogenic illness which originates from a nervous system disturbance involving excitation, loss or alteration of function.