The students, in a protest rally outside their school in Bhiwadi, were demanding appointment of teachers.
They locked the main gate of the school and blocked a highway which caused nearly 3 km long traffic jam both sides yesterday, said SHO Bhiwadi Seesram.
"They were led by some locals who also pelted stones at police which left one sub inspector and a constable injured. The area was later evacuated," he said.
A case has been registered against four local men, Dayaram, Krishna Kumar, Gajraj and Vikram, the SHO said.
No arrests has been made in this regard, he said, adding, the sub inspector and constable were given primary treatment.