CANBERRA, Dec. 16 -- An Australian social media campaign "I'll Ride with You" which urges Australians to embrace the local Muslim population has become the No.1 trending topic on Twitter in the wake of Sydney's dramatic siege.

The campaign came about during the 16-hour hostage situation at a caf in Sydney's CBD, in which two people were shot dead by Iranian cleric Man Haron Monis, before the gunman himself was killed by police.

As of 11.00 a.m. local time on Tuesday morning, the hashtag # illridewithyou was the main topic for discussion in the world on Twitter.

The campaign was launched on Monday evening when anti-Muslim feelings were running high at the scene at Martin Place in Sydney' s CBD, where the leader of the ultra-nationalist Australian Defence League, Ralph Cerminarra, was removed from the area after shouting abuse towards the caf.

A Sydney woman named Rachael Jacobs took to Facebook to demonstrate her first-hand account of how fear was beginning to affect innocent Muslims.

She spoke of one woman on a train who removed her Muslim headwear because she was apparently frightened of the public's reaction. ".. and the (presumably) Muslim woman sitting next to me on the train silently removes her hijab,"Jacobs wrote on Monday afternoon. "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."

In response, Sydney TV content editor, Tessa Kum, followed Jacobs's lead, tweeting: "If you (regularly) take the #373 bus between Coogee/Martin Place, wear religious attire and don't feel safe alone: I'll ride with you."

So began the "I'll Ride With You" campaign.

People were advised to list their means and lines of transport for the following day, before writing the hashtag, in an effort to let innocent Muslims know they could feel safe wherever they were.

Australian personalities -- such as actor Russell Crowe, human rights advocate Julian Burnside and priest Father Bob Maguire -- all tweeted the hashtag, enhancing its popularity around the globe.

Within its first few hours, the hashtag had been written on Twitter more 120,000 times from people around the world, with more taking to other social media sites such as Facebook and Instagram to send their messages of support.

According to Twitter Australia, the hashtag peaked at 1,250 tweets-per-minute on Monday evening and remained at 999 tweets-per- minute at 9.00 a.m. local time on Tuesday morning.

"It was very much a sort of breaking point for me,"Kum told ABC Radio on Tuesday morning."I saw another tweet online indicating another woman's act of kindness and I simply felt there needed to be more of that in the world."

"It just seemed that a simple way of promoting that kindness would be to say if anybody catching public transport didn't feel comfortable just because of what they were wearing, I would sit next to them, so they weren't alone."