The two convicted over the incidents in Nilphamari and Magura have faced punishment, while the suspect is yet to be arrested over the Jessore incident
In Jessore, a case was filed with the police over a class-2 student being raped, in the Jhikargacha upazila.
The victim's mother filed the lawsuit on Tuesday, accusing Nur Islam, 47, who remains a fugitive.
Jhikargacha police station Sub-Inspector Nazrul Islam said: "The incident took place on Monday, while the child was collecting firewood."
The victim has been taken to the Jessore General Hospital for medical attention and the police are currently working to arrest the suspect, he added.
In Nilphamari, police on Wednesday have arrested a man accused of raping a class-6 student in the Baraipara area.
The victim's mother filed the case on Tuesday night, accusing Sohel Rana, 19.
According to locals, the incident took place on Tuesday, in absence of the child's parents, Sohel allured her to a nearby farm and committed the heinous act.
Nilphamari Sadar police station OC Ershad Alam said: "Upon interrogation, the arrested confessed to his crime and later was sent to the district jail."
The child was taken to the Nilphamari Sadar Adhunik Hospital for medical attention, he added.
In Magura, a man has been sentenced to life imprisonment, found guilty in a rape case by the Women-Children Repression Prevention Tribunal.
The tribunal's Judge Pranay Kumar Das on Wednesday, passed his verdict.
The victim filed the lawsuit with the tribunal on May 4, 2011.
State Lawyer Adv Abu Bakkar said: "The convicted Masud Molla, 40 had committed the crime on October 13, 2010. Since the incident the victim had conceived a child. Masud was proven the father by a DNA test. The government has decided to provide child care until the child comes of age."