Australia's dramatic siege in which a gunman displayed an Islamic flag follows months of warnings about "lone wolf" attacks, and experts said authorities must think harder about how to tackle the problem.
Heavily-armed police surrounded the Lindt chocolate cafe in Sydney's financial heart Monday as an unknown number of people remained inside hours after being taken hostage.
The incident comes against a backdrop of warnings from the government about radicalised Muslims, potentially attracted to the conflicts in Iraq and Syria and sympathising with the Islamic State group.
Australia upgraded its security alert in September in the face of extremist threats, ramping up an anti-terror crackdown after foiling a plot by Islamic State jihadists to carry out "demonstration executions" in the country.
This screengrab taken from Australian Channel Seven shows the suspected gunman inside a cafe in the central business district of Sydney. (AFP Photo)
"I am deeply concerned about the threat that lone wolf terrorism poses to people," Prime Minister Tony Abbott said in September.
Anne Aly, an associate professor specialising in counter-terrorism at Curtin University in Western Australia, said radicalisation in Australia had been a gradual process over the last five years but had become more noticeable since the rise of IS.
"The jihadist narrative is one that has personally resonated with the everyday lives of some young people in Australia," she told AFP.
"If you look at that narrative, it is all about victimhood, persecution and Muslims under attack."
Lindt cafe was one commonly used by jihadist groups bearing the shahada, or profession of faith in Islam. It said: "There is no God but Allah; Mohammed is his messenger."
Australia has committed some 600 troops and several aircraft to Iraq and Abbott has repeatedly called the Islamic State group an "apocalyptic death cult".
This screengrab taken from the Australian Channel Seven broadcast shows presumed hostages holding up a flag with Arabic writing inside a cafe in the central business district of Sydney. AFP
Aly said there was a growing right-wing, nationalistic movement in Australia which made some Muslims feel like outsiders.
"They feel there is some truth to Muslims being under attack. And maybe because they feel are so far away, they feel they need to get out and do something."
- Concerns of violence -
Counter-terror expert at Charles Sturt University, associate professor Nick O'Brien, said any connection to the IS group (also known as ISIS) in the Sydney siege would not come as a surprise.
"Once we have a situation when we have Australians being recruited and travelling to the Middle East to fight for ISIS, inevitably something is going to happen here and unfortunately it looks like it has," he told Australian Associated Press.
Canberra has passed a law criminalising travel to terror hotspots and cancelled the passports of 70-plus people to prevent them heading to fight alongside jihadists, amid concerns they could return home and commit violence.
Australian National University visiting professor Clive Williams said Australia had attracted attention by committing troops to operations in Iraq, but had not so much to fear from fighters returning from Syria radicalised.
"It's the ones who want to go over there and can't go," he said, adding the siege was probably the work of a "lone wolf".
A hostage runs towards a police officer outside Lindt cafe, where other hostages are being held, in Martin Place in central Sydney. REUTERS.
"We need to think about that a bit more strategically. It needs to be a bit more sophisticated than taking away their passport."
Adam Dolnik, professor of terrorism studies at Wollongong University, said it was possible that the perpetrator was sympathetic to the Islamic State group.
"The other possibility is we are dealing with a psychopathology in need of a cause," he told AFP, adding that the gunman may have little religion or ideology.
However, he said there would be an association with Islam in most people's minds.
"Of course, that can be very damaging," he said.
The grand mufti of Australia Ibrahim Abu Mohamed said in a statement with other Muslim leaders that the community was "devastated" by the turn of events and condemned "this criminal act unequivocally".
"Any such despicable act only serves to play into the agendas of those who seek to destroy the goodwill of the people of Australia and to further damage and ridicule the religion of Islam and Australian Muslims throughout this country," they said.?