CHANDIGARH (India) - Three men have been beaten up by two sisters on an Indian bus after they attempted to assault the young women.

A video of the incident last Friday, filmed by a passenger, has gone viral across a country where abuse of women has become a raging debate and prompted tough new anti-rape laws.

The sisters, identified by the Times of India as Ms Arti Kumar, 22 and her sister Pooja, 19, had taken a bus in the northern state of Haryana's Rohtak district.

Three young men "threatened us and abused us", one of the women told the Press Trust of India news agency.

"One of them touched my sister inappropriately," she said.

When the men also made lewd comments to a pregnant passenger, the sisters decided it was time to fight back, said the Times.

One of the women told BBC Hindi: "No one came forward in the bus to help us. So we took out our belts in self-defence (and hit the men). If only the other passengers had helped us, we would not have needed to retaliate in this way."

The sisters said the men pushed them out of the bus when it stopped and attacked them again, but the women fought back by throwing a brick at the men who ran away.

The men were arrested and charged with assault.

The Haryana government has announced a 31,000 rupee (S$649) cash reward for each of the two sisters, said the Times.

It has also suspended the bus driver and the conductor, because the bus was not driven to the nearest police station and the conductor failed to intervene.