No one has been arrested so far in connection with the incident, police sources said.
The protests came even as the Allahabad High Court asked the state government and the UPPSC to seek instructions on a petition challenging the policy which proposes caste-based quotas from the preliminary exams stage itself.
Trouble started around noon when hundreds of students gathered in front of the Uttar Pradesh Public Service Commission building here to protest against the new policy.
When policemen deployed there tried to prevent them from approaching Civil Lines, the students got furious and indulged in heavy stone-pelting, the sources said.
By the time they reached the Civil Lines crossing, the protestors had vandalised several shops and vehicles parked on the roadside even as senior officials led by Inspector General of Police of Allahabad Zone, Alok Sharma, rushed to the spot.
After much cajoling, the officials succeeded in pacifying the agitators, most of whom left the spot while those who stayed back continued to raise slogans without indulging in violence, theys said.
The protestors have been alleging that the new reservation policy was aimed at benefiting members of those castes which have been traditional voters of the ruling Samajwadi Party in the state.
Meanwhile, a division bench comprising Justice Laxmi Kant Mahapatra and Justice Rakesh Srivastava asked the the state government and the UPPSC to file their counter affidavits on July 22.
The petitioners had alleged that the new reservation policy was ultra vires of the Constitution.