Photographs Of Sydney's Cafe Siege Victims, Lawyer Katrina Dawson And Cafe Manager Tori Johnson
Photographs of Sydney's cafe siege victims, lawyer Katrina Dawson (L) and cafe manager Tori Johnson are displayed in a floral tribute near the site of the siege in Sydney's Martin Place, December 23, 2014. A funeral for Johnson and memorial for fellow siege victim, lawyer Katrina Dawson were held on Tuesday, one week after both died in the siege. Reuters/Jason Reed

A radical Islamist group is calling for a Muslim army to impose Sharia law in Australia. Hizb ut-Tahrir announced that it is raising an army of followers in public at a community centre in Lakemba, western Sydney.

An estimated 250 people, including women and children, attended the public rally organised by the extremist group. Bilal Merhi, one of the group's members, told the crowd gathered at the centre that the Islamic Caliphate ruled by Sharia Law must take the place of Australia's democratic government, Seven News reported.

The Hizb ut-Tahrir told those in attendance to "come forward" to join an army "ready to defend the honour of Allah and his Messenger." Merhi also declared that Australians exploit the freedom of speech to mock Islam.

The radical Islamist organisation had previously called the Charlie Hebdo killings in Paris the "cure" in an event discussing the desire of the West to confront the "Islamist threat." Earlier reports in October had indicated that police investigated Merhi in connection with videos showing children as young as six years old being taught to chant extremist slogans.

Meanwhile, Attorney General George Brandis said people who were found to be encouraging terrorism or engaging in its advocacy will be arrested and taken off the streets. Terrorism experts believe Hizb ut-Tahrir may be crossing a fine legal line if the group continues with its activities. Professor Greg Barton, executive director of the Global Terrorism Research Centre at the Monash University said the group may see a degree of legal opposition and prosecution, leading to some key people being charged.

The terror alert level for possible attacks on police has been raised to "high" after new intelligence obtained by authorities. According to a statement released by the Australian Federal Police, the threat level for members of the police force has been changed in line with the rest of the country's terror alert.

The statement said the assessment was based on intelligence information and discussions with partners, SMH reported. Despite the active and combined efforts of state and federal police to disrupt the activities of terror networks, the dangers prompting the high terror alert last September 2014 still remains. The Australian Federal Police reminds the public of the recent terror attacks in France, Canada and the siege in Martin Place.

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