In a climate of fear and uncertainty, Australians have banded together to show their support for the Muslim population.

The #illridewithyou hashtag amassed almost 120,000 tweets on Monday evening, as Australians took a stand against anti-Muslim sentiment in the wake of the Martin Place siege.

A young Brisbane woman, Rachael Jacobs, appears to have inspired the campaign after posting a moving Facebook status about her encounter with a Muslim woman earlier in the day.

"...and the (presumably) Muslim woman sitting next to me on the train silently removes her hijab," Ms Jacobs wrote.

"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 inspiring status quickly circulated on social media before inspiring the #illridewithyou hashtag.

Sydney TV content editor Tessa Kum said she "broke" when she read Ms Jacob's story and decided to post the following message on Monday afternoon:

"If you [regularly] take the #373 bus b/w Coogee/MartinPl, wear religious attire & don't feel safe alone: I'll ride with you," she wrote.

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. — Sir Tessa (@sirtessa) December 15, 2014

She then posted a second status, featuring the #illridewithyou hashtag. Within hours it had gone viral on social media, as Twitter users from around the country offered to ride public transport with Muslims who feel intimidated by anti-Islamic sentiment.

If you wear religious attire, & need to get from #Adelaide's west suburbs to the city on Tues but don't want to travel alone #illridewithyou — Sharna Bremner (@sharnatweets) December 15, 2014

More than happy to join the #IllRideWithYou initiative. T3 or T4 from Sydenham to city and return, daily. — Jakkii Musgrave (@slybeer) December 15, 2014

"It is hard to feel hope when you feel helpless. #illridewithyou is a small act, but might be important for someone one day," Ms Kum told Fairfax Media.

"My thoughts are with those involved, who will be affected for so long to come, and those uninvolved, who are being blamed none the less."

Ms Jacobs wrote on her personal Facebook page that she was "completely overwhelmed" by the response.

"Mine was a very brief encounter - a small gesture to a stranger in response to the sadness that I felt that someone would ever feel unsafe or unwelcome because of their beliefs," she wrote.

"I'm not the story and I'm not a hero. Those who started the‪#‎illridewithyou‬ movement are incredibly inspiring and anyone who joins it is creating a path to peace for all of us."

The campaign was widely praised on social media. "Today goes to show, Australians will always come together and support one another," one Twitter user wrote.

Several politicians, media personalities and sports stars also showed their support for the campaign.

Australians tonight doing what we do best - uniting to overcome intolerance and hate #illridewithyou — Bill Shorten (@billshortenmp) December 15, 2014

Heartened to see people respond to today's events with solidarity #illridewithyou - let's not allow fear, hatred and division to triumph — Tim Soutphommasane (@timsout) December 15, 2014

Oh ... and of course #illridewithyou ... it would be a privilege. — Liz Ellis (@LizzyLegsEllis) December 15, 2014

Wonderful to see so many Australians reaching out with genuine compassion to fellow Muslim Australians with #illridewithyou. — Tim Costello (@TimCostello) December 15, 2014

The campaign seems to echo Prime Minister Tony Abbott's statement during his Monday press conference.

"Australia is a peaceful, open and generous society. Nothing should ever change that," he said.

The chart below maps the growth of the #illridewithyou hashtag in real time.