Patna, March 27 : An FIR has been filed against three teachers, including the head mistress, of a government school in Bihar's West Champaran district for brutally assaulting a Class 5 student who was five minutes late in coming back, police said on Monday. The incident occurred in a government upper middle class school located at Shankar Yadav Tola village in the district on March 23. The victim's parents filed an application with Bagaha SDM and Bathwaria police station and the matter is under investigation. As per the complaint lodged in Bathwaria police station, the victim claimed that he had taken permission to go to the toilet and head mistress Sharita Devi granted him 5 minutes for the purpose. The student returned to the student in 10 minutes which made Sharita Devi angry and she allegedly beat him. When the student argued with her, two other teachers Krishna Kumar and Dharmendra Kumar took him into a class room and brutally assaulted him after closing the door. The victim revealed his ordeal to his parents on Thursday. The parents along with other villagers immediately went to the school where they found him weeping inside the school premises. The parents immediately went to Bathwaria police station and lodged a written complaint against three teachers. The victim's father claimed that he had some dispute with Sharita Devi and she had beaten his son in anger. "After the medical examination and statements of other students, we have registered an FIR against three teachers and further investigation is underway," said Amit Kumar, SHO of Bathwaria police station. /IANS