Gunmen have reportedly taken several people hostage at a café in the central Australian city of Sydney, making them hold a black flag, apparently belonging to a Takfiri group, against a window.
According to witnesses and reports, as many as 30 people are believed to be held by at least two armed men inside the Lindt Café in Sydneys central business district.
There was no immediate confirmation of the exact number of attackers and captives.
Meanwhile, footage aired by the Australian television showed a black flag with white Arabic writings being held against a window of the place by terrified hostages.
The flag allegedly belongs to the al-Qaeda-affiliated al-Nusra Front, one of the Takfiri terror groups operating against the government in Syria.
Scores of armed police forces have sealed off Martin Place in central Sydney and surrounded the chocolate café.
Police officials said they were responding to an incident at the nearby Opera House, without elaborating. The Opera House was reportedly evacuated after a suspicious package was found there.
Martin Place is home to several prominent buildings, including New South Wales, state leader Mike Bairds office, the Reserve Bank of Australia, Westpac Bank, and the Commonwealth Bank.
In recent months, Australia has been on high alert after the Canberra government raised concerns over the return of the citizens who have joined the Takfiri terrorists operating in Syria and Iraq.
Earlier this month, Canberra said at least 20 Australian nationals fighting for terrorist groups, including the ISIL, had been killed in the two neighboring Arab states. Over 90 Australians have joined ISIL Takfiri militants there.