SYDNEY: Australians came out Monday in solidarity with the Muslim community following a siege at a Sydney cafe, as tens of thousands tweeted the hashtag #illridewithyou to counter concern about an anti-Islam backlash.

The hostage-taking at the Lindt chocolate cafe triggered a security lockdown in the heart of Australia's biggest city, with the government and Muslim leaders condemning the attack and calling for unity.

Amid uncertainty about the hostage-taker's motives and fears of reprisals after an Islamic flag was raised in the cafe, an Australian woman reportedly started the #illridewithyou hashtag to show solidarity with Muslims who might feel threatened on public transport.

“#373 bus between Coogee & Martin Place. #illridewithyou @ me if you just want to wear your headdress & not be bothered,” @sirtessa tweeted.

Within hours, Australians around the country repeated the hashtag, with more than 40,000 tweets helping #illridewithyou become one of the top trends on the social media site.

“I make a commitment, right now, to always say something when I see any kind of abuse on public transport. #illridewithyou,” one user tweeted.

Another user in South Australia wrote, “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."

Others offered help beyond travel support: “I'm mostly housebound so Im not useful for #illridewithyou but if you're ever in tarneit VIC and need somewhere safe to hide out, contact me."

Australia's race discrimination commissioner Tim Soutphommasane said he was heartened by the campaign, adding: “let's not allow fear, hatred and division to triumph."

Anti-Islam groups had earlier expressed outrage about the siege, with the Australian Defence League writing on Facebook: “Here it is folks, homegrown islamic terrorism in our backyard, courtesy of successive Australian governments and their brainwashed voters."

New South Wales Police Commissioner Andrew Scipione said officers were working with the Muslim community.

“Reprisal attacks are something that should not happen,” he added.

More than 40 Muslim groups condemned the siege, saying in a statement that they rejected “any attempt to take the innocent life of any human being or to instil fear and terror into their hearts”.