Women's groups in India are planning nationwide rallies on January 21 to protest the alleged mass molestation in the city of Bengaluru on New Year's eve, and subsequent comments by politicians blaming the women for the crime.

The India protests, publicised under the hashtag #IWillGoOut on social media, are meant to coincide with the “Million Women March” in Washington on Jan 21, the day after Donald Trump's inauguration as president of the United States.

Several women said they were groped and assaulted by a mob on a crowded central street of the technology hub Bengaluru on Dec 31, despite the presence of a large number of policemen.

The state home minister later told television networks “such incidents do happen”, while another politician blamed women for following “western culture”, dressing inappropriately and staying out late.

“That something like this could happen in a city like Bengaluru, in a crowded public space, is shocking. It could have happened to any of us,” said ElsaMarie D'Silva, founder of Safe City, an online project that collects reports of harassment and maps areas unsafe for women.

“To see these reactions from authorities who are meant to protect us is even more distressing.”

The attacks, reminiscent of those blamed on migrants in German cities last year, have shocked women across India, since Bengaluru — home to young technology professionals — is regarded as safer for women than New Delhi, which has among the nation's highest reports of rape and other crimes.

The politicians' comments echo those made after previous incidents of violence against women, including the fatal gang rape of a young woman on a bus in New Delhi in December 2012.

That incident sparked nationwide protests and led to stricter rape legislation.

It also led to a campaign by women's groups called 'Why Loiter?' that encouraged women to walk the streets of their cities at night, to defy men who said women should not be out at night following the Delhi rape.

More than 34,000 rapes were reported in India in 2015, according to the National Crime Record Bureau. More assaults go unreported because women fear being stigmatised.

The “Million Women March” in Washington is in response to Trump's attitude toward women, and fears that his presidency could set back or destroy many women's rights.

Similarly, activists hope the marches in at least a dozen cities in India will draw attention to women's rights and the patriarchal mindset that blames women and questions their right to be out, said D'Silva, who is organising the event in Mumbai.

“We don't talk enough about violence against women in this country, nor are we doing enough to prevent it,” she said.

“We must keep up the pressure on our institutions to ensure our safety, and keep pushing for a change in attitudes and behaviour towards women.”