They said a five year-old girl complained to her grandmother about the teacher, following which her parents and relatives rushed to the private school and demanded that action be taken against the man.
Senior police officials went to the spot, spoke to them and assured them that action would be taken if the teacher was found guilty, following which the man was taken for questioning, they said.
Police said other parents had told them two more UKG children had been similarly abused by the teacher and had been hospitalised.