SYDNEY - Three people ran out a fire exit of a Sydney building where a hostage situation had been unfolding since Monday morning.

It was unclear whether they were hostages or whether they were escaping another area of the building.

The people were seen on live video footage bolting out of the door past heavily armed police and then disappearing around a corner.

The development came six hours after a gunman took an unknown number of hostages in a downtown Sydney chocolate shop and café at the height of Monday morning rush hour.

New South Wales state police said they were dealing with "an armed incident." Television footage shot through the café's windows showed several people with their arms in the air and hands against the glass.

"Specialist officers are attempting to make contact [with] those inside a café," police said in a statement.

TV footage showed two people in the café holding what appeared to be a black flag with white Arabic writing on it. It was not immediately clear what the flag said. Armed officers lined up outside the café. A police spokeswoman said no injuries had been reported.

The café is in Martin Place, a plaza in Sydney's financial and shopping district packed with holiday shoppers this time of year. It is home to the state premier's office, the Reserve Bank of Australia, and the headquarters of two of the nation's largest banks. The state parliament house is a few blocks away. Area streets were closed, offices were evacuated, and the public was told to stay away.

Bloomberg News reported the U.S. consulate on Martin Place had been evacuated.