Though it was a Sunday, children had been to school to get administered polio drops.
They were, however, shocked to see the brutal thrashing of their teacher by the principal and his son.
According to the reports, the lady shikshamitra (temporary teacher) was allegedly assaulted by Om Prakash Singh, the principal, and his son in front of the students at the government primary school at Bardah in Uttar Pradesh's Azamgarh district, about 275 km from here.
The only fault of the teacher was that she made a telephone call to the principal after the latter did not reach the school even after three hours of the scheduled time to start the drive.
The matter came to light from the pictures that show the lady being hit by the principal and his son, who also carried a pistol in his hand, and lying on the ground.
Both Singh and his son have been arrested and a case lodged against them, police said.
The teacher, Sudha Singh, said that she was asked to report at the school at 8:30 hours for the purpose of administering polio drops to children.
''I made a call to the principal after the latter did not reach the school by 11:30 hours...he got furious by the call,'' she said.
Singh later turned up at the school with his son and started thrashing her.
The children ran away from there on seeing their teacher being assaulted.
Police said that the arms license of the principal will also be cancelled.