Police in New Delhi clashed with demonstrators on Saturday following the gang-rape of a female student on a bus last Sunday.
Protesters are calling for stepped-up security for women across India and changes to the way crimes against women are prosecuted there.
The protesters were demonstrating for a sixth day while the woman battles for her life in a hospital in the capital.
The government has appealed for calm as outrage over the attack intensifies.
Six drunken men were joyriding on a bus when they picked up the physiotherapy student and her male companion and took turns raping her, before throwing the pair from the speeding vehicle. Both were beaten with iron rods.
The BBC says six people have been arrested.
Police figures show a rape is reported on average every 18 hours in New Delhi and some other form of sexual attack every 14 hours.
Novelist Arundhati Roy said rape is seen as a "matter of feudal entitlement" in many parts of the country, and the reason this case came to light is because the woman belongs to the affluent middle class.
