It was on this day in 1948, when the then Hyderabad state of the Nizam was merged with the Indian Union.
Despite repeatedly being told that there was no permission for their rally, protesters argued with police and hurled stones at them near the university campus, a police official said.
"Students resorted to heavy stone pelting on police personnel after they were prevented from taking out a rally towards the Assembly," deputy commissioner of police Y Gangadhar said.
Meanwhile, the day was celebrated at the offices of ruling Congress, main opposition TDP, BJP, TRS and others.
Observing that the day is celebrated officially in those parts of Karnataka and Maharashtra which were part of the then Hyderabad state, the BJP has been demanding that the celebration be done officially by the Andhra Pradesh government.