New South Wales olice officers are handling what many suspect could be a hostage situation in a downtown Sydney cafe.

Bloomberg reports:

About half a dozen armed officers wearing helmets and body armor were stationed on the corner of Elizabeth Street and Martin Place, about 20 meters from the Lindt cafe entrance. Pedestrians were blocked from the CBD square, which houses offices for Macquarie Group, the central bank and Westpac Banking Corp.

Channel Seven showed images of people inside the cafe with their arms up pressed against the window and holding a black flag with white lettering. New South Wales police confirmed an operation was underway in Martin Place, and declined to provide further details. Sky News said the Sydney Opera House was evacuated after a suspicious package was found.

SKY News has the live video feed:

Here is a custom Twitter feed we put together of news sources in Australia:


EARLIER:

As of now, no injuries have been reported, and police have not given details as to what is happening inside the shop, or whether those seen through the window are indeed hostages. However, the Telegraph reports that the man claiming to be behind the incident in the cafe claims to have explosives planted all over the city, and has demanded to speak with Australian Prime Minister Tony Abbott live on the radio.

The Telegraph’s correspondent out of Pakistan has provided an explanation of what the writing on the flag says, and what the presence of the flag could signify:

“There’s a lot of discussion about the nature of the flag hanging in the coffeeshop window. It represents the Shahada, an Islamic creed which reads: “There is no god but the God, Mohammed is the messenger of God”. However, putting it on a black background some suggest it has been appropriated as an Islamist symbol.”

Abbott has rallied Australia’s National Security Committee for an emergency briefing, and is urging the public to remain calm. As I said above, police have not confirmed that this is indeed a hostage situation, and we don’t have details about who may be responsible for whatever it is that’s currently unfolding in Sydney.

We’ll keep you updated.

7 News Sydney also has a live feed running:

Police negotiators are now in contact with the gunman, and there’s still no information suggesting that anyone has been harmed (and some have escaped):

Earlier, at least three people were seen inside the Lindt cafe with their hands up against a window, and holding up a black flag with Arabic writing.

Australian Prime Minister Tony Abbott has described the “terrifying” incident as “deeply concerning”.

About six hours into the siege, three people were seen running from the building housing the cafe. Two more people followed about an hour later. The circumstances of their exit are not clear.