Hundreds of students in Allahabad went on a rampage Monday against the changed reservation policy of the State Public Service Commission and attacked the commission building and vandalised over 100 public vehicles.
Police resorted to a mild cane charge to disperse the mob.
Allahabad Deputy Inspector General of Police N. Ravindra told IANS that the students were protesting against the changed reservation policy in the 2011 Uttar Pradesh Public Service Commission (PCS) exams.
Students earlier had filed a writ petition in court challenging the reservation policy.
The angry students also vented their ire at all vehicles carrying flags of the ruling Samajwadi Party and on hoardings of the party.
Extra police force has been deployed and the situation is now under control, police officials said.
Allahabad is 220 km from the state capital.