The Mangalore pub incident where women were attacked has put Hindu nationalists in India in a bad light, whose behaviour has been compared with Afghanistan's hardline Taliban.
Five men also briefly kidnapped a Hindu girl from a bus, incensed that she was travelling with a Muslim boy.
All the incidents happened in the city of Mangalore in the southern state of Karnataka, where there has also been communal violence against Christians.
India's minister for women and child development, Renuka Chowduri, has warned that Karnataka is in the grip of "Talibanisation" suggesting that women are being oppressed there as they were by the Islamist militia in Afghanistan.
The violent pub attack, claimed by the radical Hindu group Sri Ram Sena (SRS), or Lord Ram's Army, has prompted fierce debate about the role of women in modern India and changing values in this conservative country.
For the SRS, the young women smoking, drinking and dancing in a trendy Mangalore bar at the end of January were indulging in "debauched" behaviour that had to be punished.
But Indian women have vowed to defend their freedoms and rights, which have been transformed in recent years -- at least in some urban areas.
SRS head Pramod Mutalik, who was arrested after admitting he was behind the pub attack, has set his group up as the "custodians of Indian culture" and protector of women he says need to be prevented from "going astray".
This puts him on a collision course with the more Westernised way of life taking hold in big cities such as Bangalore, a vibrant regional capital dubbed India's Silicon Valley because of its wealth of IT and software firms.
Mutalik was released on bail, and immediately warned that any couples found courting in public on Valentine's Day risked being taken to the nearest temple and forced to marry.
Leading English-language daily The Hindu has described the SRS as a "Hindu Taliban," accusing them of fascist behaviour. The weekly current affairs magazine Outlook also warned of the "Talibanisation of Karnataka".
"This kind of event is really shocking. They cannot stop women in such a way. Nobody has the right to do that," said Bharka Singh, from the Delhi Commission for Women.
"Times are changing and the condition of women has changed, even if we still respect tradition."
The ruling Hindu nationalist Bharatiya Janata Party (BJP) in Karnataka has condemned the violence, the latest in a string of attacks by small groups of radicals uneasy about the direction and pace of change in India.
Calls for a boycott of Valentine's Day have even been heard in India's most cosmopolitan city Mumbai.
In northern Uttar Pradesh state, two police officers were suspended for beating a couple for hugging in public. Radical Hindus have also targeted female students wearing jeans and short skirts, or talking to boys.
Just this month, judges at the Delhi High Court threw out an attempt to prosecute a young couple for obscenity after they were seen kissing in public.
"These people don't seem to understand that there isn't one India. India is so big, so diverse and so different," said Rukshana Shroff, an English teacher at the Sri Rama College for Women in New Delhi.
"Sometimes the same thing is a problem in one place and not in another. The solution and the key is tolerance."
Many suspect that political motives underlie the furore, with right-wing nationalist groups, who see themselves as the custodians of so-called Hindu values, seeking to grab the spotlight ahead of elections expected in April.
But for Singh, the incidents expose the difficulties created by a fast-growing economy that has widened the gap between urban and rural India, introducing outside influences and challenging traditional gender roles.
"(The SRS) are afraid of progressive women," she said.
"In villages, in the countryside, these men are scared because they still want to dominate women.
"These Sri Ram Sena men are from low castes they only saw women in saris before, so when they see women in jeans, sexy, smoking and dancing, they feel frustrated."