Rosie Percy, a London journalist, says she was touched on the escalator and reported the incident to British Transport Police. She says she had to give her statement three times, including explaining what trousers she was wearing and which buttock was touched, which was "pretty harrowing".

Rosie Collins, another member of the audience, says that women should be able to use the emergency stop button to report this type of harassment.

Siwan Hayward, from Transport for London, is in the audience and she says TfL has been committed to encouraging reporting of harassment.

"We have seen 100% increase in reporting and 50% increase in convictions" but she noted that one in seven women will have experienced unwanted interaction in the last 12 months.

Ellie Cosgrave, research associate on the 'Livable Cities' Project and a member of #teamgo, says "there is a sense of entitlement that women are men's property".

Liz Kelly, who has been talking about the issue in schools, says boys and girls "understand this issue so differently... we are trying to help [boys and men] change the culture itself to stop it from happening in the first place".

Image source, bbc

Nancy, our presenter, asks how many people taking part in the live debate have experienced some kind of harassment and almost all the hands in the room go up.

How many reported it, she asks? Just 3 or 4....

Join in the discussion with #100Women

Image source, PA

Tanya Baron, CEO of Plan International UK, called sexual harassment on public transport a "vital, global discussion."

She said "horrendous inequalities" result in abuse of "young women and girls on all sorts of public transport".

She says only 27% of people in the UK think its safe for women to use the tube at night.

Because of this her organisation are bringing lessons from other countries back to London.

She says that you have to involve boys and young men into these discussions.

Our panellist Hanne Bingle from #teamgo talks about the difficulty for train conductors to tackle incidences of sexual harassment. She used to be a tube driver for TfL.

She says "the practical solution would be for staff to meet you" but because of scale of tube network, this is difficult.

Image source, bbc

The women on our debate panel and who are working on the #teamgo challenge throughout the week are:

• Hanne Bingle, an ex-Transport For London tube driver who is looking at female self-defence
• Ellie Cosgrave, external, who works on the 'Liveable cities' project and is looking at how to re-engineer cities
• Anne-Marie Imafidon, external, creator of Stemettes which works to get more girls into male-dominated professions
• Laura Jordan Bambach, external who advocates for women in creative industries
• Liz Kelly, external, a professor of sexualised violence and co-chair of End Violence Against Women coalition in the UK

You can follow their progress on BBC 100 Women page and on our Facebook, external, Instagram, external and Twitter, external

Join in the debate by tweeting #100Women

Image source, Getty Images

Khadija from Sanaa in Yemen sent us a Whatsapp to tell us she found the Arab Spring made street harassment worse.

"Back in 2012-13... I remember street harassment reaching new heights. I would be subjected to groping or attempted groping every time I went out. I would simply punch anyone who touched me inappropriately. It started to create anxiety problems, until I just stopped going out."

She says programmes are needed to educate men and boys, and women need to be helped in reporting harassers.

Anita Dderu was groped while travelling on a public bus in Nairobi

More than half of women in Kenya have experienced gender-based violence on public transport, according to a recent study.

The BBC's Nancy Kacungina is leading our discussion from the Transport Museum in London for the third of our 100 Women challenges.

You can listen to the BBC's Outside Source's live coverage here.

We have women from a wide range of industries and backgrounds, who are there to discuss sexual harassment on public transport and how we can combat it.

If you have any thoughts on this subject please let us know on Twitter by using the hashtag #100Women.

Sian Lewis is a sociology expert who researches sexual harassment on public transport.

But when she herself was harassed on a bus she did not report it to the authorities. She told BBC 100 Women why not.

Keep an eye on this live page for the latest updates, or head over to our Facebook page, external to take part in a Facebook Live at the same time.

This week the 100 Women Challenge is based in London and is asking a group of inspiring and influential women to come up with products or campaigns to tackle sexual harassment on public transport.

The five members of #teamgo are at the London Transport Museum for a debate on World Service radio to brainstorm ideas.

They are joined by a group of guests who have experienced, witnessed, or are looking into ways to prevent harassment on public transport.

You will be able to listen to the debate on BBC World Service Radio's Outside Source programme from 16:00 GMT (17:00 BST).

Join in and help #teamgo come up with solutions - send your ideas in via Facebook, external, Instagram, external and Twitter, external and use #100Women