The incident took place in the jurisdiction of Gadasarai police station here.
The victims, students of Class XI of a local school, had been admitted in the district hospital in a serious condition with burn injuries to their hands and faces, Sub Divisional Officer of Police (SDOP) Bhagat Singh Gothria said.
He said a manhunt had been mounted for the motorcycle- borne men.
Officials quoting eyewitnesses said the attackers had also covered their bike's number plate.