Police registered a case against the motor vehicle department driver, who hit the girl, arrested and later released him, police said.
The girl was admitted to a district hospital and later discharged, they said.
The motor vehicle department driver lost his cool after the girl's grandfather, who was asked to stop the vehicle for routine check, said he would drop his granddaugter in the school and return.
Protesting against the incident, angry passersby blocked traffic on Kollam-Shencottai national highway for some time.