The decisions were taken at an emergency meeting in the evening.
Aritree Adhikari, a Class-IX student, reportedly committed suicide at their Shantinagar residence in the city on Monday after allegedly being rebuked by teachers for using mobile phone during examination.
Following the incident, the victim's father Dilip Adhikari filed a case against three teachers of the school.
It sparked a wave of outrage inside and outside the school and students demonstrated at the campus for three days demanding justice over the incident.
Later on Wednesday, the governing body of the school suspended its three teachers -- acting Principal Nazneen Ferdous, morning shift in-charge of Bailey Road branch Jeenat Akhter and Aritree's class teacher Hasna Hena-- over the suicide case.
A Dhaka court on Thursday sent Hasna Hena to jail after detectives in a drive arrested her from the city's Uttara area on Wednesday night.