In a show of solidarity, many Australians have offered on Twitter to accompany people dressed in Muslim clothes who were afraid of a backlash from the cafe siege.

The hashtag #IllRideWithYou had been used more than 90,000 times by the evening.

Today's siege at the Lindt Chocolat Cafe in central Sydney continued with police trying to secure the release of hostages.

The spark for the campaign was a post on Facebook by Rachael Jacobs,. She reportedly said she'd seen a woman she presumed was Muslim silently removing her hijab while sitting next to her on the train: "I ran after her at the train station. I said 'put it back on. I'll walk with u'.  She started to cry and hugged me for about a minute - then walked off alone'.

 

The hashtag #IllRideWithYou has since been trending on Twitter in Sydney and other major Australian cities, with public transport users offering to act as buddies for anyone who might be too nervous to appear in public wearing religious garb.

Tens of thousands of Twitter users have already offered their support.

It's believed Twitter user "SirTessa" was the first to suggest the initiative, writing: " If you reg take the #373 bus b/w Coogee/MartinPl, wear religious attire, & don't feel safe alone: I'll ride with you. @ me for schedule."

Others across Sydney and beyond were quick to join in.

Mia Lazzarini tweeted: "I'm in. If u wear religious garments & feel unsafe on public transport, I'll sit with u. Redfern-KX, peak hrs. #illridewithyou".

Another user, Polly Maeve, wrote: "I only ride a short distance to and from the city on the Belgrave/Lilydale/Alamain lines, but #illridewithyou. #racismstopswithme".

One user said he hoped to inscribe badges with the message, while others have begun printing labels bearing the hashtag and pinning them to bags and clothing.

Sydney-based lawyer and prominent Muslim woman Mariam Veiszadeh told the Press Association the movement was "heartwarming".

She was in a morning conference when news of the siege broke, and said she burst into tears when she learned there was a possible Islamist link: "I said, I'm sorry, and I know it's obvious, but I need to say these lunatics don't represent my faith."

She said she was unable to find a taxi to take her all the way home from work as demand surged in Sydney on Monday afternoon, but that another office worker - a stranger - insisted on driving her the final stretch to her door.

She said when symbols of the Islamic faith are co-opted by terrorists or criminals, "there tends to be an outpouring of support".

But she added: "It often unfortunately goes hand in hand with the vitriol that Muslims often get exposed to, and women often bear the brunt of that."