Indian police used bamboo canes on Friday to disperse supporters of a government plan to reserve more college seats for lower castes.
The low caste medical students in Patna, in the eastern state of Bihar, were marching to back an affirmative action program that has led to doctors and medical students across India going on strike.
The strike is forcing thousands of hospital patients to go without treatment or to seek treatment at costly, private hospitals in New Delhi.
The government plans to more than double the percentage of places reserved for lower caste students in state-funded medical, engineering and other professional colleges.
Critics say the change will reduce the number of slots for students competing on merit and will hurt educational and professional standards.