Growing outrage over the gang rape of a woman on a bus in New Delhi has led to crowds of protesters demanding a crackdown on crimes against women.
The outpouring of anger is unusual in India where attacks against women are often ignored and rarely prosecuted.
Opposition MPS called for the death penalty for the rapists.
Demonstrations erupted outside New Delhi's police headquarters demanding swift punishment for the rapists, and university students set up roadblocks across the city.
Six men raped the 23-year-old medical student, and beat her and a male friend with iron rods before throwing them off the bus last Sunday.
The woman is in a critical condition in hospital and doctors said she has severe internal injuries.
Delhi police chief Neeraj Kumar said four men have been arrested and they were searching for the other two.
Home Minister Sushilkumar Shinde told parliament that he had ordered increased police patrols on the streets, especially at night.
Mr Shinde said the government has proposed amendments to criminal laws to increase the punishment for rapes and other crimes against women. But they are still awaiting discussion and passage in parliament.
Analysts and protesters said the upsurge of anger was chiefly due to the increasing incidents of crime against women and the seeming inability of the government and police to ensure the safety of women.